Castellanos’ 2017 expected weighted on-base average was nearly 40 points higher than his actual 2017 weighted on-base average. That meant the quality of his approach and contact were not being fully realized by his statistical production. That realization came to be in 2018 as he had his best overall season for run production. The step up was not a huge one, but it was continual growth at a time we want to see it from a young player. A contributing factor to the surge in batting average was the fact he hit .381 against lefties over 162 plate appearances. He has had quite a bit of batting-average variance in recent seasons against lefties, with a low point of .207 just two seasons ago, but has overall feasted on them while coming in slightly above average overall against righties. His defense is significantly behind his offense, and another defensive move to first base may come sooner rather than later.

Lost in a sea of disappointing performances for the Tigers in 2017, Castellanos was quietly a bright spot for the organization as he set new career-high totals in home runs (26), runs (73) and RBI (101), while lowering his strikeout rate to 21.4 percent. As the season progressed, he showed increasing power, slugging .553 in the second half while putting the ball in the air more frequently (43.6 percent flyball rate). Interestingly, Castellanos showed good power to all fields, pulling 10 homers, hitting seven to center field and nine the opposite way. As the Tigers reshape their roster for a possible long-term rebuild, the supporting cast may continue to erode, but the opportunity for a more favorable spot in the batting order could help offset that, as he hit third or fourth throughout September after Justin Upton was traded to Anaheim. He'll likely move to the outfield again with Jeimer Candelario positioned to play third regularly, but Castellanos should have every opportunity to settle in as a heart-of-the-order run producer in 2018.

Castellanos has three full seasons in the majors before the age of 25, but it wasn't until last season that he returned plus value at the plate. His strikeout rate and walk rates are both remarkably stable for someone of his age, but the batting average and power both jumped in 2016. His isolated power metric has improved each of the past three seasons as he continues to hit flyballs at a higher rate each season and mostly of the pull variety. He was an odd hitter in 2016 in that he was much better against righties, as a righty, than was against lefties. He hit .315 against right-handers (.207 against lefties) and had 13 of his 18 homers against righties. For his career, he has been rather split neutral but last year could be a side-effect of him working on pulling more baseballs. He's entrenched as Detroit's third baseman and could continue to improve at age 25.

Castellanos failed to take the expected step forward last season. He continued to boot balls at third base and delivered decidedly mediocre offensive numbers (.255 with 15 home runs, 73 RBI and a .721 OPS). He struck out about once a game, just like he did in his rookie year. Still, criticism of his offensive future seems a bit premature — the guy will be barely 24 on Opening Day and still has a number of years to fulfill his potential as a middle-of-the-order hitter. Castellanos' game picked up after the All-Star break and he had his best month in August (.286 with a .900 OPS), but don't expect dramatic growth in his game in 2016. He'll bat down the order and focus on incremental improvement on both offense and defense.

As the Tigers’ top positional prospect heading into the 2014 season, many pundits had high hopes for Castellanos. On the surface, Castellanos had a mediocre first full season in the majors, hitting .259/.306/.394 with 11 home runs, 66 RBI and 54 runs in 533 at-bats while serving as the Tigers’ full-time third baseman. Similar to his results in the minors, Castellanos had trouble with his plate discipline, finishing with 24.2% strikeout rate and 6.2% walk rate. He also struggled defensively, ranking last in the majors at UZR for third basemen. The defensive struggles can partially be chalked up to the Tigers juggling Castellanos between the outfield and third base in 2013. With a full-year of playing third base at the major league level under his belt, Castellanos should show improvement on defense. And some of the advanced metrics behind Castellanos’ performance at the plate during his rookie campaign hint at further growth to come. Castellanos did a great job limiting infield flyballs (2.1% IFFB) and he ranked second among qualified hitters with a 28.5% line-drive rate. The Tigers appear to be committed to Castellanos as the team’s third baseman of the present and future, so he will have a long leash to work through the issues that arose throughout his rookie campaign. The 23-year-old showed consistent improvements in both plate discipline and power as he made his way through the minors, and it wouldn’t be a surprise to see similar improvements as he becomes acclimated to the majors.

Castellanos is the Tigers' top prospect and widely considered a top-25 prospect league-wide. He validated the high praise from scouts in 2013 by putting together a solid campaign during his first taste of Triple-A ball. In 533 at-bats with the Mud Hens, Castellanos hit .276/.343/.450 with 18 homers and 76 RBI. While his batting average dipped below .300 for the first time in his minor league career, Castellanos made great strides in the power department, as his 18 homers topped the 17 total home runs he had racked up through 1,068 at-bats the previous three seasons. He also flashed improved plate discipline, raising his BB/K ratio to 0.54 and his contact rate to 81 percent. The 22-year-old had his first exposure with the Tigers during a September callup. Castellanos was primarily deployed against left-handed pitchers, finishing with a .278 batting average in 18 at-bats. Despite the lack of playing time during his initial promotion, Castellanos is expected to battle for a full-time role in spring training. Following the trade of Prince Fielder to Texas in November, Castellanos is expected to be converted back to third base after spending the past season and half in the minors learning the outfield. While he initially projects to be more of a gap hitter in the majors, Castellanos' frame (6-foot-4, 210 pounds) and swing hint at 20-25 home-run power as he develops. Perspective owners will want to watch Castellanos closely during spring training to see if he can earn a full-time role with the Tigers. If he nabs the gig, Castellanos will be considered a preseason candidate for AL Rookie of the Year honors.

Castellanos, the Tigers' 2010 sandwich pick rocketed up the prospect rankings last season. He started off the season with High-A Lakeland, where he slashed his way to a .405/.461/.553 line in 215 at-bats before getting bumped up a level. At Double-A Erie, Castellanos saw his line drop to .264/.296/.382 in 322 at-bats. His production in Erie was obviously a step back, but it's still solid production for a 20-year-old seeing his first action in the higher levels of the minor leagues. One big boost in value that came from his promotion was a position change from third base to the outfield. At the hot corner, Castellanos was blocked by Miguel Cabrera for years to come, but a move to the outfield has sped up his clock. Now, Castellanos could factor into the roster mix for the Tigers as soon as this season. With just 17 homers in 1,068 at-bats in the minors, Castellanos has not fully flashed his power stroke yet, but his large frame (6-foot-4, 210 pounds) and extra-base power (32 and 36 doubles the past two seasons) hint at power that will develop down the line. He might not make much of a fantasy impact this season, but Castellanos' potential should have dynasty owners salivating at his potential a few years from now.

The Tigers selected Castellanos in the supplemental first round of the 2010 draft. Ranked as one of the best high school hitters in his draft class, Castellanos has quickly lived up to the hype. During his first full season of pro ball, Castellanos hit .312/.367/.436 with 46 extra-base hits in 507 at-bats for Low-A West Michigan. Castellanos struggled a bit with his plate discipline (45:130 BB:K), but his batting eye should improve with more time in the minors. He's also considered a solid defender at the hot corner, so his defense won't hold him back from moving through Detroit's system. In fact, Detroit already believes in Castellanos enough to have traded fellow third base prospect Francisco Martinez prior to the 2011 deadline, so his path to the majors is wide open. At 20, Castellanos could still use some extra time to develop, but he appears on track to make a splash in Detroit as soon as 2013.