Tracking the so-called greatest free-agent class ever

Bryce Harper and Manny Machado highlight an incredible crop of upcoming free agents. Who is doing the most to help his value so far this season? Rob Carr/Getty Images

The so-called greatest free-agent class ever took a hit when Charlie Blackmon signed a long-term deal to remain with the Colorado Rockies rather than hit free agency after this season, but it's still a deep class with lots of volume -- if now slightly less star power.

Throughout the season, we'll take a peek at the some of those pending free agents, how they're trending and any buzz that might be out there. We're only a couple weeks into the season, so let's start with an overview of some of the more interesting players who might hit the market.

Bryce Harper

Trending up: How do you become a $400 million player? By playing like Harper has so far. He's locked in, hitting .316 with six of first 11 hits going over outfield walls and drawing walks at prodigious rates. This is the Harper we saw for six months in 2015.

What's left to prove: That he can do it for a full season. He got off to a similar start in April 2016, when he hit nine home runs, only to play through some shoulder issues and finish with a .243 average and 24 home runs. Oh, and a playoff series win wouldn't hurt.

Predicting the market: Harper Watch will be the most-watched free agency since LeBron took his talents to South Beach. What's interesting is the usual big spenders might not be involved. The Yankees already have Aaron Judge and Giancarlo Stanton (though Brett Gardner could be a free agent). The Red Sox have three good outfielders plus J.D. Martinez. The Dodgers might have to worry about first re-signing Clayton Kershaw. That's why many believe Harper ultimately ends up back in D.C., though other wild rumors include Harper reuniting with Las Vegas pal Kris Bryant with the Cubs.

Five potential fits: Nationals, Cubs, Phillies, Giants, Dodgers. Don't sleep on the Giants. Corner outfielders Hunter Pence and Andrew McCutchen are both free agents, wiping off $33.25 million from the payroll.

Manny Machado

Trending up: He's off to a good start after posting career lows in average (.259) and OBP (.310) last season. He can handle third base or shortstop, giving him two position options in free agency (though it obviously seems that he would prefer to remain at shortstop in the future).

What's left to prove: Come to play every night. His walk rate fell from 9.8 percent in 2015 to 7.3 percent last year. So far, it's back up again, a good sign that he's more focused every at-bat.

Predicting the market: Don't assume he's going to the Yankees, as they like young third baseman Miguel Andujar, they traded for Brandon Drury, and Didi Gregorius is still under control through 2019. Of course, with the Orioles off to a slow start, the Machado trade rumors will intensify sooner rather than later.

Five potential fits: Orioles, Phillies, White Sox, Yankees, Blue Jays.

Clayton Kershaw (can opt out)

Trending sideways: Kershaw has allowed four runs in three starts and has a 19/3 SO/BB ratio, so all looks OK on the surface. There is some minor concern about his fastball velocity, which has averaged 91.3 mph, down from 92.9 last season. It could be nothing; it's only three games. Plus, he's a guy who has relied on three plus pitches, command, expert "tunneling" and that deceptive delivery more so than pure velocity.

What's left to prove: His back issues always linger in the background, so making 30 starts after missing time each of the past two seasons would make the Dodgers -- or somebody else -- a little more comfortable offering him a long-term deal.

Predicting the market: It's hard to envision Kershaw going anywhere but the Dodgers, but he'll almost certainly opt out of the remaining two seasons on his current deal … which means seeing what might be out there.

Five potential fits: Dodgers, Rangers, Yankees, Phillies, Giants (just kidding, Dodgers fans).

Josh Donaldson

Trending sideways: Donaldson began the year with a weird dead arm that caused him to chunk a couple throws to first base and end up DHing for a week, but he's back at the hot corner.

What's left to prove: Few players have matched his value on the field over the past five seasons (in fact, only Mike Trout has a higher WAR among position players), but since he's a late bloomer, Donaldson isn't hitting free agency until he's 33. He has to show that he can still play at an MVP-caliber level to give teams confidence that they can get at least three or four more great seasons from him. With his athleticism and intensity, I do think he'll age maybe akin to a guy such as Jeff Kent, who was productive through age 39.

Predicting the market: The Blue Jays are more likely than the Orioles to remain in the playoff chase and also are more likely to re-sign their free agent, so Donaldson is far less likely to get traded than Machado. As for free agency, one idea: Donaldson to the Angels, with Zack Cozart sliding over to second base to replace Ian Kinsler (who is a free agent).

Five potential fits: Blue Jays, Braves, Angels, Phillies, White Sox.

David Price (opt-out)

Trending up: After last season's elbow issues and run-ins with the media, Price came out firing, with two scoreless outings to start the season while throwing his cutter a lot more often. A rough inning Wednesday that he exited with what appears to be a non-serious hand injury make Price's start tougher to judge, but the signs of a return to being the David Price of old are still there.

What's left to prove: Health. He averaged 218 innings per season from 2010 to 2016 and led the AL with 230 in 2016 in his first season with Boston.

Predicting the market: Price is less likely to opt out than Kershaw, since he would have four years and $127 million remaining on his contract. If he has a big year and wants out of Boston, however, he'd hit free agency at 33, though I'm not sure he can top 4/127.

Five potential fits: Yankees, Rangers, Nationals, Padres, White Sox.

Patrick Corbin

Trending up: Corbin has a 2.45 ERA through three outings, with a blistering 29 strikeouts in 18.1 innings, and there might be a legitimate reason for his start: He has increased the usage of his slider from 38 percent to 47 percent, and the miss rate has gone from 45 to 65 percent.

What's left to prove: Can the new approach, which includes more sinkers, continue to work as batters make some adjustments?

Predicting the market: Corbin turns 29 in July, so he'll be younger than most pitchers when they reach free agency. He does have a Tommy John surgery in his past, but left-handers with plus stuff don't come around too often.

Five potential fits: Right now, just about anybody. His price goes up if he continues to pitch this well.

Matt Harvey

Trending down: He had good results his first start and poor results his second start. In watching both games, I can't say the stuff in either outing was particularly impressive. His fastball has been 92.3 on average, down even from last season and down 2 mph from 2016. Again, it's early, and both games were in cold weather. He's basically been fastball/slider so far, essentially ditching his curveball.

What's left to prove: A lot.

Predicting the market: All depends on performance.

Five potential fits: Nationals (Scott Boras connection!), Rangers, Mariners, Orioles, Marlins.

Andrew McCutchen

Trending down: He's had a couple walk-off hits for the Giants, but his overall line is a blah .217/.265/.326 with 11 strikeouts and three walks. He'll be 32 entering free agency.

What's left to prove: It was in 2014 that he posted a .300/.400/.500 line, so those days are long in the past. At his age, he's not going to get a huge payday or long-term contract. He isn't a center fielder anymore. That means his bat is going to have to carry him.

Predicting the market: In terms of age and production, I'd compare him to Jay Bruce, who got a three-year, $39 million deal this past offseason. At that money, it puts a lot of teams in play.

Five potential fits: Rockies, Indians, Giants, Orioles, Mariners.

Andrew Miller

Trending sideways: There are a lot of potential closers and setup men hitting the market, including Miller, Craig Kimbrel, Cody Allen, Kelvin Herrera, Brad Brach, Sean Doolittle and Zach Britton. Miller turns 33 in May, but his ability to go more than three outs -- especially in the postseason -- might make him the guy everybody wants.

What's left to prove: He did miss some time in 2017 with knee tendinitis, and his K rate was down a bit last season (38.9 percent) from 2016. It's possible that 2015-16 will prove to be his peak.

Predicting the market: Relievers were the one group that was in demand this past offseason. Even though there's a glut of them hitting the market, that should be the case again. Miller will likely get to pick his destination, and his choice could depend on whether he wants to close.

Five potential fits: Astros, Dodgers, Angels, Cardinals, Indians.

Brian Dozier

Trending up: He has been a slow starter the past couple seasons, finishing with a flourish both years -- 23 home runs the final two months of 2016 and 17 last season -- but he's off to a hot start, with four home runs and an OPS just over 1.000 this season. He has perfected his pull-happy, high launch angle swing to hit 76 home runs from 2016 to 2017.

What's left to prove: Like others in their early 30s, Dozier needs to show no signs of decline. He'll be 31 when he hits free agency.

Predicting the market: Everyone has power these days, but not everyone has a power-hitting second baseman. Defensive shifting has allowed teams to worry less about range at second base, so Dozier should be able to remain there well into his 30s. He'll be in demand. Note that Daniel Murphy, DJ LeMahieu and Ian Kinsler will also be free agents, so there will be a glut of second basemen.

Five potential fits: Twins, Dodgers, Brewers, Nationals, Angels.