Five players in make-or-break seasons

Keith Law will unveil his Top 100 prospects on Wednesday (you can find his organizational rankings here) so I thought I'd look at five former top-100 prospects who are entering crucial, make-or-break seasons.

Dustin Ackley, OF, Mariners

Age: 26 in February

2013: .253 AVG/.319 OBP/.341 SLG, 4 HR in 384 AB, 1.1 WAR

ZiPS projection: .253/.327/.365

The second overall pick in 2009, Ackley was hailed was one of the best pure hitters to come from the college ranks in years. He showed promise as a rookie in 2011, hitting .273, but fell apart in 2012, hitting .226; his confidence was perhaps shattered by Safeco Field. He tinkered with his swing for 2013 and that resulted in a slow start and a demotion to Triple-A, a move that also resulted in a switch back to the outfield (where he had played in college) as Nick Franklin replaced him at second base.

After a month in Triple-A purgatory, Ackley returned and hit much better: .285/.354/.404, including .301 from July 6 on. However, after he had turned into a solid defensive second baseman, Ackley looked out of place in center field, with poor reads and a mediocre arm. With Robinson Cano on board, Ackley is no longer a second baseman, at least in Seattle, but at this point his bat doesn't profile well for left field, where he'll probably end up in 2014.

What to expect: Mariners fans point to those second-half numbers and believe again in Ackley. Here's my concern: He hit .257 against fastballs in 2013 with no home runs. He did increase that to .314 in the second half. Still, that was with no power. If you can't punish fastballs, you're not going to be anything more than a marginal hitter. If Ackley doesn't hit this year, he's destined for a career as a utility man, playing second base and outfield. Kind of a younger version of Skip Schumaker.

Starlin Castro, SS, Cubs

Age: 24 in March

2013: .245/.284/.347, 10 HR in 666 AB, -0.6 WAR

ZiPS projection: .280/.319/.413

Ah, the enigma that is Starlin Castro. After hitting .300 as a rookie and .307 as a 21-year-old, he looked not just like a budding star, but a budding superstar. But his game has stalled. His power hasn't developed; he didn't run as much in 2013 (22 steals in 2011, down to nine in 2013); he still swings at too many pitches outside the strike zone; and he ranked first or second in the league in errors for the fourth year in a row. The fans got to him, and while he was out there every day once again (he has missed five games in three years), some question how much he really wants it.

Believe it or not, there's still some good news. Castro's line-drive percentage in 2013 was the same as it always was -- 22 percent, according to Baseball-Reference.com, versus a career mark of 21 percent. ESPN Stats & Information had him at 19 percent, but compared to a career mark of 19 percent. In other words, he pretty much hit as he always has. Line drives usually result in hits, but Castro's BABIP (batting average on balls in play) was well below his career norm. So it appears he hit into a lot of bad luck in 2013.

So he should improve in 2014 just based on that. But can he be something more than a .300 hitter with 12 home runs? Is there more power to come? This is the year we should find out.

What to expect: ZiPS is optimistic about a rebound, but not overly optimistic. In the end, Castro isn't a patient hitter so he's never going to draw many walks to boost his OBP. (Well, never say never.) Would a more patient approach help? Probably, but after four years in the league -- even at his age -- you wonder if he is what he is at this point.

Ike Davis, 1B, Mets

Age: 27 in March

2013: .205/.326/.334, 9 HR in 317 AB, 0.2 WAR

ZiPS projection: .232/.320/.424

Like Ackley, Davis got off to a horrible start and was hitting .161 in June when he was demoted to the minors. He straightened out his mechanics in Triple-A and hit .267/.429/.443 the rest of the way, until a strained oblique finished his season at the end of August.

After signing Curtis Granderson and Chris Young, the Mets will thankfully move Lucas Duda out of the outfield, setting up a spring training battle with Davis at first base. Duda hit .223, so this won't exactly be a McCovey-Cepeda situation going on here.

What to expect: I still like Davis, although it's probably time to admit he'll never hit lefties. As a platoon first baseman, his value rests in a good eye at the plate, which can give him a respectable on-base percentage despite a low batting average. Still, he's prone to long slumps, as in the first half of 2013 and the first half of 2012. The Mets are probably wary of Davis by now, so look for Duda to win the job and Davis to be shopped around. He'd be a good fit for the Pirates, who need somebody to platoon with Gaby Sanchez. Either way, if Davis doesn't win a regular job, he'll probably drift into a Russell Branyan-like vagabond career, going from team to team as a fill-in first baseman.

Desmond Jennings, CF, Rays

Age: 27

2013: .252/.334/.414, 14 HR in 527 AB, 3.0 WAR

ZiPS projection: .249/.326/.403

Jennings is a good player, as witnessed by his 3-WAR seasons the past two years. He does a little of everything -- some power, steals some bases, solid defender in center, draws some walks. The question isn't whether he's going to be a guy teams can count on, but whether he'll make a leap and become the All-Star once envisioned of him. He's entering his age-27 season and has two full seasons under his belt. Now is the time.

What to expect: Jennings has to improve against off-speed stuff. Among 140 qualified regulars, his .193 average against "soft" pitches ranked 125th. (The major league average was .242.) Twelve of his 14 home runs came against fastballs. ZiPS is projecting 2014 numbers that are similar to 2013; considering Jennings has nearly 1,500 PAs now in the majors, that's probably what to expect, although I wouldn't be surprised to see a breakout performance.

Devin Mesoraco, C, Reds

Age: 26 in June

2013: .238/.287/.362, 9 HR in 323 AB, 0.0 WAR

ZiPS projection: .251/.313/.421

Mesoraco's bat was supposed to be his calling card, but in his first chance at extended playing time he flopped with a sub-.300 OBP. Mesoraco doesn't have the service time of Ackley and Davis, and catchers can take longer to develop at the plate, so his leash is a little longer. Mesoraco's defense was better than expected in 2013, as he threw out 29 percent of runners (league average was 28 percent). Still, he'll turn 26 this season, so his time to turn into an above-average player or All-Star performer is starting to wane.

What to expect: Veteran Ryan Hanigan is gone, so the Reds have handed the keys to Mesoraco. Considering the Reds' lineup after Joey Votto and Jay Bruce is pretty spotty, they desperately need Mesoraco to improve his numbers. I have my doubts. He didn't hit righties at all last year (.212/.254/.322) and he walked even less in the second half. The ZiPS numbers may be optimistic, although it's possible he could crack 20 home runs playing in Great American Ball Park.

Let's look at five pitchers on Wednesday.