MLB Trade Rumors: 15 Top Prospects Who Are Untouchable This Winter

Now that the Brewers have joined the 27 other teams who will be watching the World Series from the comfort of their living rooms, the real hard work begins.

Not only does their front-office have to figure out how to keep Prince Fielder, or how to let him go, depending on what best suits their needs, they also have to start piecing together a team for 2012, with upgrades to a few key parts.

No team did a better job of improving their roster with eyes towards a playoff run this year than Milwaukee. They sacrificed the top talent from their farm system in exchange for stability in their rotation. They dealt their top hitter (Brett Lawrie) and top two pitchers (Jake Odorizzi and Jeremy Jeffress) to get Zack Greinke and Shaun Marcum. Those two additions allowed the team to breeze through the regular season and steamroll the Diamondbacks in the NLDS, but it wasn't enough to get them past the Cardinals.

Which makes you wonder...was a run that fell short of the desired goal worth one of the top prospects in baseball?

Only time will tell how good Lawrie will be in Toronto, but no doubt the Brewers failure to advance to the World Series will certainly cause many other teams to reconsider who in their farm system they consider untouchable.

So without further ado, I present the top 15 untouchable prospects in baseball.

Austin Romine, C, New York Yankees

Whether or not the Yankees resign C.C. Sabathia, they're still going to have some issues.

Derek Jeter and A-Rod are shells of their former selves, Mark Teixeira still has a tendency to disappear for large chunks of the season, and MLB saves champ Mariano Rivera is approaching 42 years old. Not to mention the numerous injury concerns (Pedro Feliciano, Rafael Soriano, etc.).

Signing soon-to-be free-agent C.J. Wilson is a start, but it's likely going to take some pretty aggressive moves by GM Brian Cashman to plug all the leaks, meaning several of the team's top prospects could be on trade alert.

Top overall prospect Jesus Montero looked brilliant during a late-season cameo, so it's likely his job is safe, but as anyone who's seen him play can testify to, he's no catcher. On the other hand, Austin Romine, who made a brief appearance in the big-leagues this past season, has excellent defensive skills (.990 career fielding percentage). He's also not too shabby with the bat, posting a career. 281 average.

With Montero destined to move to first base or the DH spot long-term, it's likely Romine is the team's future behind the plate. If the team does decide to part with him, the next closest guy they have in the pipeline is Gary Sanchez, who just finished his first season in Low-A ball.

Manny Banuelos, LHP, New York Yankees

The Yankees have always been hesitant to turn over key roles on their big-league squad to unproven rookies. They took a chance this season with Ivan Nova and were happily rewarded with a 16-4 record and a 3.70 ERA.

Nova's success might cause the Yankees to give another talented youngster a chance. Banuelos looked sharp in Double-A last season and showed the ability to adjust to more advanced hitters during a seven-game stint in Triple-A to end the season.

He now has 80 minor league appearances under his belt, including 64 starts, and looks to be nearly big-league ready at age 20.

Keep in mind too that Banuelos was one of the best pitchers in spring training this past season, striking out 14 in just 12.2 innings and posting a sub-2.20 ERA.

Will Middlebrooks, 3B, Boston Red Sox

With the Red Sox apparently making headlines wherever you look, it seems like the last thing the team would want to do is deal a promising, young player like Middlebrooks for a stop-gap piece.

Make no mistake, the Sox collapse down the stretch this season was traumatic, and is likely to shape how they're going to build their team for the next few seasons. If Ben Cherington really is the guy who is going to replace Theo Epstein, then it's likely that Middlebrooks is staying put.

Both front-office gurus have an incredible loyalty towards their farm systems. After all, building such an entity was their pride and joy.

With half of their roster occupying at least some time on the DL this past season, Middlebrooks could find himself playing a vital role on the 2012 squad, especially now that he's proven himself to be not only a sensational hitter (.285, 23 HR in 2011), but also a seasoned defensive whiz at third base.

Dayan Viciedo, 1B, Chicago White Sox

It's too soon to tell what kind of manager Robin Ventura is.

Will he be the kind of coach who prefers veterans or will he show more inclination to letting the younger players figure things out at the big-league level, even if that means watching them and the team struggle?

Either way, the rookie manager would be out of his mind to consider parting ways with Cuban slugger Dayan Viciedo, who has looked sharp in back-to-back seasons. After a 20 home run campaign in 2010, Viciedo hit .308 with five homers in just 38 games for the Sox. He made his second big-league appearances late this past season, showing less pop (one HR in 29 games), but much better patience.

Viciedo has been blocked the past few season at his natural position, first base, but has since taken to the outfield in order to increase his versatility. Regardless of his position, he still represents the White Sox best offensive minor leaguer.

Nick Castellanos, 3B, Detroit Tigers

Castellanos came this close to being traded around the trade deadline, less than one full season before pulling on a Tigers uniform.

He was one of three players considered by the Mariners as a "player to be named later" in the Doug Fister deal. Tigers reliever Chance Ruffin ended up biting the bullet and packing his bags for Seattle.

Castellanos, on the other hand, enjoyed a breakout season. The 19-year-old hit .312 over 507 at-bats for Low-A West Michigan. He showed skill in just about every area, clubbing 36 doubles, driving in 76 runs and playing adequate defense.

He more than proved his label as the best pure hitter from the 2010 high-school class accurate, and as such, would be a major loss to Detroit's system if they ended up moving him for another veteran.

Jurickson Profar, SS, Texas Rangers

If the Rangers are going to be a major player in the offseason, something they indicated with their intentions to pursue C.C. Sabathia if he's available, it only stands to reason that they might be looking for some talent in the trade-market as well.

They certainly have the ammo, with one of the best and deepest farm systems in baseball. One player they will almost certainly NOT give up, however, is talented youngster Jurickson Profar.

Just 18 years old, Profar has already shown the ability to dominate Low-A hitters. He had a sensational full-season debut, hitting .286 with 37 doubles, eight triples, 12 homers and 23 steals for Hickory. Even more impressive, he walked two more times (65) than he struck out (63), an unheard of feat for a player of his age.

Profar has the defensive chops to match his offensive potential as well, and even though the Rangers are currently set with Elvis Andrus at short, Profar isn't going anywhere anytime soon.

Julio Teheran, RHP, Atlanta Braves

Despite his ugly stat line in the big-leagues (5.03 ERA, 10-to-8 K:BB), there's no way that the top pitching prospect in the minor leagues gets dealt before next season.

The Braves might entertain offers for Arodys Vizcaino or Randall Delgado, or heck, maybe even Mike Minor, but there's no way they're going to risk giving up a player who has the potential to be as special as Teheran.

The 20-year-old carved up Triple-A hitters this past season, to the tune of a 2.55 ERA and 122-to-48 K:BB ratio, and looked like a seasoned veteran, despite being five-to-10 years younger than most of his competition.

Toss in the fact that he throws in the mid-to-high 90s and features two great breaking balls that have yet to reach their full potential and he has all the makings of a future staff ace, even in Atlanta where they seemingly have several of those types of pitchers (Tommy Hanson, Jair Jurrgens, Tim Hudson).

Trevor May, RHP, Philadelphia Phillies

The Phillies showed no hesitation at the deadline, dealing top pitching prospect Jarred Cosart to Houston in exchange for Hunter Pence.

The move worked out for the Phillies, as Pence was a catalyst down the stretch, but in the end they lost to St. Louis and are at home watching the World Series like everyone else. With Ryan Howard out maybe until next year's All-Star break and Jimmy Rollins proving to be one of the least clutch hitters in baseball, the Phils might be on the market for a few pieces over the offseason.

One guy who won't be on the market, though, will be Trevor May. He more than picked up the slack that was left when Cosart departed. May finished third in the minor league strikeout race, with 208, and was in contention for top honors heading into the final week. Unfortunately, he could only muster 11 in his final two starts and fell behind Edwar Cabrera and Matt Moore. Still, the right-hander surpassed his career mark of 182 set last year. 

He showed incredible stamina, posting a career high 151.1 innings and tossing three complete-games. He continued to be stingy with the long-ball, serving up just eight in 27 starts. He was named the FSL Pitcher of the Week twice.

With a rotation full of aging veterans, the team is going to one day have to turn to the younger arms in their system for support, and May will be one of the first to get the call.

Brad Peacock, RHP, Washington Nationals

As evidenced by the massive Jayson Werth contract, the Nationals are all in from here on out.

In 2012, Stephen Strasburg will return to their rotation fully healthy and he'll be joined by a talented group of young pitchers. The team has already been rumored to be incredibly active in the free-agent market as well, with the intention of making a run at the Braves, Phillies and whoever else stands in their way of a playoff spot.

As such, it might make sense to shed a few lesser pieces, such as Brad Peacock, an under-performing right-hander who blossomed into a staff ace this season. 

Peacock dominated Double-A, picking up wins in 10 of his 16 outings, posting a 2.01 ERA and striking out an astonishing 129 batters in a mere 98.2 innings. His strikeout rate was, dare I say, Strasburgian. During his time at Harrisburg, he was twice named the Eastern League Pitcher of the Week, received his first All-Star nod and was named to the Team USA Futures Game squad.

After the break, he received a promotion to Triple-A, where he kept up his high level of play and consistency. He won five of his nine starts, posted a solid 3.19 ERA and had twice as many strikeouts (48) as walks (24).

As good as Peacock was, it's hard to envision him pitching much better than he did this season, which means he's likely destined for a back-of-the-rotation spot or possibly a middle or long-relief role.

Still, the Nats have developed some of the best back-end starters and relievers in the game the past few seasons, and I have no doubt that Peacock could be incredibly valuable in whatever role they find for him.

Taylor Green, 3B, Milwaukee Brewers

Who knows what is going to happen in Milwaukee after this season?

They seemingly put all their eggs in the 2011 basket and could see Prince Fielder leaving now that their dream season has ended at the hands of division rival St. Louis. Losing Fielder would leave a gaping hole in the team's lineup and at first base.

One intriguing option would be Taylor Green, a minor league vet with six season under his belt. He's a steady run producer (91 runs in 124 games in 2011) and has some great pop (71 career HR). For a third baseman, he's also pretty adept at first base, having made a handful of starts there over the years. Green has also logged some time at second base as well, making him even more valuable to the Brewers.

The team shed several of their top prospects last season, including Brett Lawrie, Jake Odorizzi and Jeremy Jeffress, in order to acquire the pieces that keyed their 2011 playoff run, but with a weakened farm system, they can hardly afford to do the same thing to compete in 2012.

Wily Peralta, RHP, Milwaukee Brewers

As evidenced by Chris Narveson's performance in the postseason (6.35 ERA in five outings), the Brewers would have been in trouble if they needed a fifth starter, assuming they made it past the Cardinals and into the World Series. 

The 29-year-old journeyman has been a solid fifth starter for the Brewers during the regular season the past two years (23-17 with a sub-5.00 ERA), but they'd be hard-pressed to rely on him for a third consecutive season expecting the same kind of results.

Enter Wily Peralta.

The burly right-hander had easily the best campaign of any Milwaukee minor leaguer this past season, posting 11 victories and 157 strikeouts in 150.2 innings. He was an innings-eater and looked downright dominant in a late-season cameo in Triple-A.

Peralta could fill several roles for the team next season, either as the fifth-starter or as a reliever. His stuff is plenty good, including a mid-90s fastball and an above-average breaking ball.

I would find it incredibly unlikely that the Brewers would trade away their top pitching prospect two years in a row.

Starling Marte, OF, Pittsburgh Pirates

I could see how it would be tempting to float Marte's name out there during the offseason.

The Pirates already have an All-Star center fielder in Andrew McCutchen, who is entering the prime of his career, and while Marte's ceiling doesn't appear to be as high, he's still an amazing athlete who would draw more than his fair share of interest.

Which is exactly why the Pirates should hang on to the youngster.

Marte finally put everything together this year and had a monster season. In addition to his first All-Star nod, he was also named to the Futures Game World roster and looked exceptional performing against the best prospects in the game.

He hit .332 in 129 games, all with Double-A Altoona. He ranked near the top of the Eastern League leaderboard with 38 doubles, eight triples and 91 runs. He also paced his own squad with 24 steals and finished second in home runs and RBI. For his efforts, the 22-year-old outfielder earned team MVP honors, in this his fifth year with the Pirates.

Even if McCutchen continues to get even better, the Pirates could always slide Marte over to one of the corners and have two outstanding defenders manning two-thirds of their outfield.

Yonder Alonso, 1B/OF, Cincinnati Reds

Listening to Buster Olney on the B.S. Report this week opened my eyes to the idea of the Reds potentially dealing Joey Votto.

And while it might not make the most sense to trade a guy two years removed from a National League MVP season, especially when he followed up that campaign with another very strong season (.309, 29 HR, 103 RBI), the Reds happen to have that luxury because of Alonso.

In the 24-year-old, the Reds have another hot-hitting player whose best position is first base. Alonso shined in his 41-game trial with the big-league club, hitting .330 with five homers and 15 RBI. He also proved that he's not the most agile outfielder, leaving his long-term future open for speculation.

Certainly, the Reds could net more by moving Votto than Alonso, and with a team that has several holes, it might not be the worst idea.

But only if they hold on to Alonso.

Matt Szczur, OF, Chicago Cubs

Lost in all the talk about Theo Epstein heading to the Windy City has been the fact that the Red Sox are demanding compensation in the form of one or more prospects. The most talked about player who could be headed to Beantown is the Cubs top overall prospect, Brett Jackson.

And while he would be a solid addition to the Sox farm system, the Cubs could afford to lose him, but only because they have a far more talented player in former Villanova football star Matt Szczur.

The 22-year-old-has a sensational full-season debut, finishing the season in High-A ball. He hit .293 with 10 homers and 46 RBI and showed some of the most blinding speed in the minors. He swiped 24 bases in 29 attempts and dazzled with his play in the outfield.

If Jackson gets packaged in the deal for Epstein, that is a sure-fire sign that the Cubbies value Szczur more.

Tyler Skaggs, LHP, Arizona Diamondbacks

The D-Backs made a surprising run at the pennant this year, winning the National League West by eight games over the defending champion San Francisco Giants.

And while a couple of key pieces to their run were acquired from outside the organization, namely Daniel Hudson and Ian Kennedy, the majority of their impact players were homegrown (Justin Upton, Chris Young, Josh Collmenter).

Next season, however, the pressure will inevitably be on Arizona to repeat their performance from 2011, and they'll be facing a stiffer challenge as the defending division champs. Taking that into account, it wouldn't surprise anyone if they tried to acquire a few more key pieces to keep their roster strong.

Skaggs is still likely a year away from making a major impact on the big-league roster, so I could see how it would be tempting to deal him away for a player who could make a more immediate impact, but with the free-agent and trade-markets being as weak as they are, it's unlikely that they'll find another player, specifically a pitcher, who will have as much upside as the 20-year-old lefty, who struck out nearly 200 batters last season in just 158.2 innings.