Every March, I post a list of players who I think are primed for significant upticks in performance for the coming season. These are players who already have lost their rookie status but either haven't performed at all in the majors or perhaps just haven't lived up to expectations.
Last year's list had several players who did indeed break out, including Charlie Morton, Byron Buxton, James Paxton (I said 20 starts and 3-4 WAR; he made 24 starts and produced 3.8 WAR) and Orlando Arcia, plus two guys who suffered injuries that affected their performances last year but whom I still like going forward in Addison Russell (shoulder) and Eduardo Rodriguez (knee). Rodriguez flashed a better breaking ball in spring training last year, but it didn't last, and that remains his biggest flaw as a starter.
This year's list has nine players on it, all aged 22 to 25, including a couple of former top prospects looking for their first real taste of big league success.
These choices come from my own historical evaluations of players, a look at recent performances, and conversations with scouts and coaches this spring about which players look better in some way or otherwise seem primed for a breakout. I've included a line at the end mentioning prospects who have impressed scouts this spring and who might also make a significant impact in the majors at some point this season.
Lucas Giolito, RHP, Chicago White Sox: The White Sox have helped Giolito restore his old delivery, rediscover the tight spin on the plus curveball he had as an amateur and even add a second "two-seam" changeup to his pitch mix, which already included a slider and straight change. He's throwing harder this spring, again commensurate with what he was doing as an amateur and in his first full year back from Tommy John surgery. I do worry he'll be a little homer-prone between his four-seamer, which is still fairly straight, and the White Sox's homer-friendly park, but I am optimistic we'll see an above-average line from Giolito this season with a huge strikeout total.
Ian Happ, INF/OF, Chicago Cubs: Happ's major league home run output last season was a surprise -- 24 homers in 115 games after hitting 24 in 160 games total between High-A, Double-A and Triple-A -- but there's more room for improvement in his contact rate and batting average. Happ punched out 32 percent of the time last year in the majors after never exceeding 24 percent at any minor league stop. He runs deep counts, and his two-strike approach so far has been "swing harder." In our current environment, that's not just viable -- it's potentially productive. I wouldn't project 30 homers for Happ, as it seems like some regression is inevitable given his prior production, but I would bet on enough improvement in his average and OBP to more than balance that out.
Nomar Mazara, OF, Texas Rangers: Mazara seemed to stall a little bit in his sophomore year in the majors, especially as it became clear to pitchers that they could attack him with off-speed stuff low or outside of the zone. He still made enough hard contact when he did put the ball in play that he should hit for higher averages going forward, although his swing right now is more geared to using the whole field than it is for big power. He has earned raves from Rangers people this spring for his mental approach to the game, his confidence at the plate and his work on areas such as improving his at-bats against lefties. He has never been undisciplined at bat, giving me reason to think he'll have better results on contact this season and, for example, reduce how often he rolls over off-speed stuff to the opposing first baseman.
Daniel Norris, LHP, Detroit Tigers: I admit I don't love seeing that Norris' velocity was sitting at 90-91 mph in one recent outing, but I'm still listing him on the basis of his outstanding athleticism, his improved control in his looks this spring and the change in the Tigers' coaching staff. He seems to have gotten past the delivery issues that bedeviled him early last season, when he'd over-rotate and release the ball too early. It doesn't seem like he'll make the Tigers' rotation to start the season, but that's fine; he could work effectively in long relief for a few weeks and move into the first opening in the rotation. A full-season breakout for Norris might look like 120-130 innings of league-average performance.
Jameson Taillon, RHP, Pittsburgh Pirates: Taillon hasn't been able to catch a break since he was the No. 2 overall pick in 2010 between Bryce Harper and Manny Machado. He has had Tommy John surgery and a hernia injury, which combined to cost him all of 2014 and 2015, took a liner to the head in 2016, and then was diagnosed with testicular cancer in 2017, missing just a month after surgery to treat the disease. There's really no good reason why he should allow a .357 BABIP to right-handed batters again this season given his plus sinker/plus slider combination. Even with some remaining platoon split, he should be much more effective this season and drop his ERA a half-run or more.
Blake Snell, LHP, Tampa Bay Rays: Snell started to break out in the second half last season, as his command of his off-speed stuff improved, especially his curve (which became a big swing-and-miss pitch for him) and changeup. Snell has long had the stuff to be a No. 2 starter but rarely the command or even the control, but it seems like that came together last fall and has continued into the spring. He's also doing a better job of using his fastball to set up his three potentially above-average secondary pitches. I expect above-average performance from him no matter how much he ends up starting for the Rays.
Max Kepler, OF, Minnesota Twins: Kepler's development has been slower than most prospects, probably because he has such an unusual background for a position-player prospect growing up in Germany, which has a nascent but still underdeveloped baseball culture. He reached full-season ball at 20 and had his breakout season in the minors at 22 between High-A and Double-A, hitting .318/.410/.520 with 65 unintentional walks and just 68 strikeouts. In two seasons in the majors, he has been a below-average offensive corner outfielder but has posted modest swing-and-miss rates (mostly tied to off-speed recognition) and good exit velocities. Everything has happened on the late side for Kepler, and I think the same is true of his ability to pick up breaking stuff from lefties and changeups from righties, enough so that I expect him to reduce his platoon split this season and get to 25-plus homers with a league-average or better OBP.
Xander Bogaerts, SS, Boston Red Sox: Although power across the game went up last season, Bogaerts' disappeared, as he dropped from 21 homers in 2016 to just 10 last year. His exit velocity also plummeted; in 12 fewer plate appearances last season, he had 32 percent fewer balls in play with exit velocities of at least 100 mph compared to the previous season. He dealt with a hand injury for half of the season after he was hit by a pitch in early July and tried to play through pain rather than taking time off for it to heal. Bogaerts always projected to hit for 20-plus homers, showing easy power as a teenager in A-ball, and I fully expect him to bounce back to his 2016 power levels and probably even exceed them.
Teoscar Hernandez, OF, Toronto Blue Jays: Hernandez might not have a clear route to playing time just yet, but of all the Blue Jays' many outfield candidates, I like his upside the most and think he's ready to show that offensive potential right now. He makes hard contact with a swing that produces above-average power, can run enough to play all three outfield spots and add value on the bases and has a plus arm. He is not going to be a strong OBP hitter -- and showed some weakness in September as teams attacked him with four-seamers at the top of the zone -- so his upside is limited compared to that of other names on this list. I do think he could be a 20 homers/20 stolen bases hitter who adds value with defense but loses some with an OBP in the .300-.310 range.
Rookies who've looked good: SS J.P. Crawford, Philadelphia Phillies; LHP A.J. Puk*, Oakland Athletics; RHP Taylor Clarke*, Arizona Diamondbacks; RHP Mike Soroka*, Atlanta Braves; INF/OF Yairo Munoz, St. Louis Cardinals; OF Adolis Garcia, St. Louis Cardinals; RHP Diego Castillo*, Tampa Bay Rays. (*Already reassigned to minor league camp.)