MLB Free Agents 2017: Early Buzz and Predictions for Hitters on Expiring Deals

The start of Major League Baseball's free-agent signing period is still months away, but buzz is already starting to circulate the rumor mill regarding some of the biggest hitters slated to hit the market this winter. 

So as the second half of the season starts to wind down and pennant races come into clear view, here's a look at a few notable outfielders whose situations will be worth monitoring once the offseason gets underway.

As a bit of housekeeping, bear in mind predictions were made with more general parameters in mind, since interested teams won't make themselves known until hot stove season ramps up.  

J.D. Martinez

J.D. Martinez should cash in when the offseason starts. 

Although he's slumped (.226/.328/.623) since getting dealt from the Detroit Tigers to the Arizona Diamondbacks in advance of the non-waiver trade deadline, the 29-year-old right fielder is a power-packed force who can change the complexity of a lineup when he's penciled into the heart of the order. 

Dating back to his debut in 2011, Martinez has posted 129 home runs and an .837 OPS. During that seven-season stretch, those marks rank 20th and 15th among all outfielders, according to FanGraphs. 

Those are numbers worth paying for, and they should vault Martinez into an esteemed financial tier when all is said and done. 

As things stand, Martinez's $11.7 million salary ranks 25th among outfielders. 

Based on his pure power numbers and lifetime .282 batting average, Martinez stands to crack the top 15 average annual salaries among outfielders at a minimum. 

In fact, he could vault as high as the top 10 if he's able to crank things up as the postseason approaches. 

"There's always that little bit of added pressure or stress that goes into it, because everybody's always talking about it," Martinez said of his impending free agency, per USA Today's Bob Nightengale. "Everybody reinforces it on you. I'm just trying not to think about it and just play the game.

"But I think it definitely helps going to a contender."

Martinez remains something of a net-negative defensively, but it shouldn't be hard for power-hungry teams to overlook those shortcomings and open their wallets to land arguably the best position player on the market. 

Prediction: Martinez garners a multi-year deal that pays north of $15 million annually

Justin Upton

Justin Upton is playing on a pseudo-expiring deal through the 2021 season since his mammoth six-year, $132.7 million deal with the Tigers includes a player option each of the next four seasons. 

Just don't expect him to hit free agency anytime soon. 

While the 29-year-old could conceivably garner another major long-term commitment if he hits the open market since he's slashing .315/.411/.630 with a 1.042 OPS, six home runs and 24 RBI since the All-Star break, passing up a guaranteed $22.1 million payday doesn't appear to be in the cards. 

FanRag Sports' Jon Heyman reported in May that Upton declining his player option at this juncture "seems beyond remote" and noted that one general manager told him it's "not happening." 

Upton's mammoth annual salary ranks third among outfielders behind Jason Heyward and Yoenis Cespedes, and that figure may be hard for the Tigers to swallow through 2021. 

However, that's a long way from now. 

With Upton still producing like one of the game's premier corner outfielders at the plate, the Tigers shouldn't have any qualms about Upton returning to the fold as a centerpiece in 2018 and beyond.  

Prediction: Upton exercises his 2018 player option and returns to Detroit

Jay Bruce

The New York Mets couldn't find a taker for Jay Bruce at the non-waiver trade deadline despite the team's best efforts. 

According to Newsday's Marc Carig, there's a reason for that. Citing rival executives, Carig reported Bruce wasn't coveted by rival teams because his "worth is rooted primarily in hitting for power at a time when teams generally have placed more of an emphasis on speed and defense."

On the surface, that assessment seems fair. Bruce owns a .249 lifetime average and .319 on-base percentage. 

That said, his defense has been solid all season long and can't be overlooked as he prepares to become a free agent. 

According to FanGraphs, Bruce currently ranks tied for second with Aaron Judge among all right fielders with seven defensive runs saved this season. The only player with a superior mark is Mookie Betts, who is blowing his positional peers out of the water with 30 DRS.  

"I'm not sitting here saying that I'm Jason Heyward or Yasiel Puig or Mookie Betts or anything like that," Bruce said, per Carig. "But that’s a bit of a broad stroke, a lazy approach to judging me as a defender."

Bruce figures to have a hard time matching the $13 million he's earning in 2017 once he's eligible to field offers, but a multi-year contract in the range of $8-10 million a year is reasonable for a power hitter and fielder of his ilk. 

Prediction: Bruce re-signs with the Mets on a two-year deal  

Stats courtesy of Baseball-Reference.com unless noted otherwise and current through Monday, Aug. 7.