MLB Prospect Watch: 10 Players on the Verge of Being Called Up

This is an exciting time for Major League Baseball prospects. 

It was just a matter of time before it happened, but right now, both Mike Trout and Bryce Harper are in the majors at the same time, probably for good. Harper has looked very good in the early days of his major league career, and Trout enters Friday with a modest three-game hitting streak. Both of them are only going to get better.

The question now is which top prospects are going to get the call next. Might we see Trevor Bauer get called up in Arizona? How about Lonnie Chisenhall in Cleveland?

I'd like to venture some educated guesses about 10 prospects who could get the call to the show in the near future.

Nolan Arenado, 3B, Colorado Rockies

The Colorado Rockies offense has been working just fine so far this year, but they've gotten next to nothing out of their third basemen. Chris Nelson is hitting .224 on the season, and Jonathan Herrera has hit .222 when he's had to play third.

It's just a matter of time before the Rockies look to their farm system for an answer to their third-base woes, and Nolan Arenado will be right at the top of their list of options.

The Rockies drafted Arenado in the second round back in 2009, and he's developed into quite the hitter. He had more RBI than any player in the minors in 2011, and so far this year, he's batting .299 in 27 games with Double-A Tulsa, according to MiLB.com.

Arenado will be in the majors this year—sooner rather than later. I doubt we're talking about a matter of days, but surely, a matter of weeks. If he isn't called up by the end of this month or in early June, I will be very surprised.

Trevor Bauer, SP, Arizona Diamondbacks

Heading into the season, four of the five spots in Arizona's starting rotation looked solid as a rock.

The fifth spot, however...not so much.

Sure enough, Josh Collmenter fumbled away his spot in Arizona's rotation (see AZCentral.com). Pat Corbin has been given a chance to hold on to it for him, but he's not going to last long if he's as unpredictable as he was in his debut on Monday.

The Diamondbacks have two great pitching prospects to call on in Trevor Bauer and Tyler Skaggs. Between the two of them, my hunch is that Bauer will get the call first. For the better part of the season, he's been tremendous for Double-A Mobile, while Skaggs has had his ups and downs in recent starts.

Bauer is often compared to Tim Lincecum—and for good reason. He pitches like Lincecum, and his stuff is a lot like Lincecum's stuff was when he first got called up to the big leagues. Major league hitters will struggle to get used to it initially, and that's something the Diamondbacks can take advantage of.

I expect to see Bauer in the big leagues before the end of the month.

Lonnie Chisenhall, 3B, Cleveland Indians

The Indians have to be very pleased with what they've gotten from Jack Hannahan this season. He hasn't gotten on track defensively yet, but he's hitting .290 with a .375 OBP. That's not bad at all.

But down on the farm, Lonnie Chisenhall has been even more impressive. In 22 games with Triple-A Columbus, Chisenhall is hitting .326 with four home runs and 12 RBI, according to MiLB.com.

The bad news? A calf strain has landed Chisenhall on the disabled list, according to Indians beat writer Jim Ingraham. It doesn't sound like it's anything serious, but it will put him on the shelf for at least a little while.

The Indians will keep Chisenhall down at Triple-A as long as Hannahan continues to hit. His track record suggests he's not going to be able to flirt with a .300 average for long, so Chisenhall will just have to be patient.

Chisenhall's time will come. He's Cleveland's long-term answer at third, and the Indians would no doubt love to see him, Asdrubal Cabrera and Jason Kipnis all on the same infield. 

I'm expecting to see Chisenhall get called up some time in June.

Heath Hembree, RP, San Francisco Giants

The Giants started the season with a very strong bullpen, but injuries have taken their toll. Brian Wilson is gone for the season after having Tommy John surgery, and Jeremy Affeldt has suffered yet another freak injury (see the San Francisco Chronicle).

The Giants are one more injury away from having to make a move. If they need to make said move, Heath Hembree should be the first guy they think of.

Hembree has been terrific closing games for Triple-A Fresno this season. Per MiLB.com, he has a 1.64 ERA in 11 innings, allowing just five hits in the process.

He's a prototypical late-inning reliever. His fastball can climb as high as 99 miles per hour, and he has a nasty cutter/slider-type pitch that eats hitters up.

Nothing seems to be imminent when it comes to Hembree. But at the rate their bullpen is eroding, it's a good bet the Giants are going to need him pretty soon.

I'm setting the target at late May.

Danny Hultzen, SP, Seattle Mariners

King Felix rules the top of Seattle's starting rotation. After him, Jason Vargas is pretty solid.

After him, all bets are off. The back end of Seattle's rotation promises to consist of moving parts all season long, and one guy who is sure to be involved at some point is Danny Hultzen.

The Mariners drafted Hultzen second overall in the 2011 draft. He doesn't have lights-out stuff, but he's more of a polished pitcher than most prospects thanks to his productive career at the University of Virginia.

Hultzen has taken to Double-A Jackson quite nicely. Per MiLB.com, he has a 2.05 ERA in five starts. He's allowed six earned runs all season, and five of those came in his very first start. Since then, he's been money.

An injury will open the door for Hultzen, but simple ineffectiveness could do the trick too. Given the collective buffoonery at the back end of Seattle's starting rotation, it's a virtual lock that Hultzen will be in the majors in the near future.

I'm setting the ETA at mid June.

Brett Jackson, CF, Chicago Cubs

The Cubs are one of the most inept offensive teams in the majors. The only regulars in their lineup who are scary are Starlin Castro and Bryan LaHair. The rest of it is decidedly "meh."

Chicago's outfield, in particular, is dragging the team down with its lack of production. It could use a boost.

Brett Jackson could be said boost. He was money after he got the call to Triple-A last season, and so far this year, he's off to a pretty solid start. Per MiLB.com, he's hitting .252 with a .350 OBP in 25 games with Triple-A Iowa.

Jackson only has two home runs this season, but he definitely has pop in his bat. He hit 20 home runs last season, including 10 in just 48 games with Iowa.

My guess is that the Cubs won't be calling Jackson up at any point in the next couple days. They'll bide their time with him, waiting for the right opportunity to call him up (injury, etc.).

But Jackson's time will probably come before the All-Star break. Mid June sounds about right to me.

Matt LaPorta, 1B, Cleveland Indians

Casey Kotchman has gotten off to a very slow start for the Indians at first base, as he's hitting just .162 in 20 games. 

Manny Acta said recently (via MLB.com) that no moves are imminent. It's just too early in the season to freak out, especially seeing as how Kotchman is an established veteran who hit over .300 last year.

But Matt LaPorta is definitely on the radar in Cleveland. All he's doing at Triple-A Columbus is batting .371 with nine home runs and 20 RBI in 24 games, according to MiLB.com.

We've seen LaPorta destroy minor league pitching before. In fact, he barely qualifies as a "prospect" at this point in his career. He's had his chances in the majors, and he's failed to establish himself.

If Kotchman doesn't snap out of his funk, LaPorta will get another chance very soon. Even if Kotchman does snap out of it, LaPorta will be heard from sometime before the All-Star break.

I think we'll see him get the call before the month is over.

Mike Montgomery, SP, Kansas City Royals

It was obvious from the start that Kansas City's starting rotation was going to be an adventure this season. Not surprisingly, the Royals start Friday with a 5.39 rotation ERA, and the staff's BB/9 is well over 4.00.

Yuck.

The Royals are going to mix and match with their starting rotation this season. One guy who has to be on the major league radar is Mike Montgomery.

Montgomery has been just okay for Triple-A Omaha this season. In five starts, he has a 4.55 ERA and hitters are hitting him at a .296 clip, according to MiLB.com.

He's been solid lately, however. Montgomery has pitched at last six innings in each of his last three starts, allowing six earned runs in the process. Better yet, he's walked only four in his last three outings.

Montgomery needs to keep this up. If he does, the Royals will have an easy call to make when they sit down to discuss rotation options.

I'm thinking mid June sounds about right for Montgomery.

Ryan Wheeler, 3B, Arizona Diamondbacks

The Diamondbacks are being patient with Ryan Roberts. He's off to a horrendous start, but the team owes it to him to give him some time to recapture his form from last season.

They can't wait forever, though—not in a division as tough as the NL West. If Roberts' slump continues, the D-Backs will have no choice but to make a move.

Ryan Wheeler will be at the top of their list of options. He's been outstanding for Triple-A Reno this season, batting .315 with a .537 slugging percentage through 27 games, according to MiLB.com. In his last 10 games, he's batting .463.

Wheeler has some pop in his bat. He hit 16 home runs last year and 12 the year before that.

Roberts should consider himself on notice. He's not untouchable, and Wheeler is too hot to ignore right now.

His promotion will become a legit possibility before the end of the month.

Alex White, SP, Colorado Rockies

As expected, Colorado's starting rotation hasn't been great this season. It got a little thinner this week, as the Rockies sent Jhoulys Chacin down to Triple-A to work out his issues, according to the Associated Press.

The Rockies are going to need a starter for Monday, May 7th, now that Chacin is out of the picture. Alex White will be available to start that day.

White was one of the key pieces the Rockies got in return for Ubaldo Jimenez last year. He struggled in the majors last season, but he's been pretty good for Triple-A Colorado Springs this season. Per MiLB.com, he has a 2.92 ERA in five starts.

The timing checks out OK if the Rockies want to use White on Monday. His last start was on Tuesday, in which he went 4.2 innings.

So, I'll call it right now. White's going to start on Monday.

If not, he'll surely get the call soon after.