Texas has been connected to both through various rumors, but the circumstances are different. Ozuna is a left fielder and would displace Willie Calhoun, who made significant progress in his development last season.
Castellanos has primarily been a right fielder the past two seasons after being moved from third base by the Tigers in 2017. The Rangers would likely have him play first base, which means Ronald Guzmán being bumped aside. Guzmán has not come around offensively the way that Texas had hoped.
Who would be the better fit for the Rangers? It may come down to the size of the contract, but …
Castellanos appears to be right for the Rangers.
Let's break it down further:
Hitting vs. left-handers
Ozuna did not have a good year against lefties last season, batting .217 with a .270 on-base percentage and a .482 slugging percentage -- but that appears to be an exception. In 2017, he hit .307/.385/.425 and for his career he is .291/.341/.497.
Castellanos hammered left-handers last season with a .370 batting average, .425 on-base percentage and a .713 slugging percentage. His .935 OPS against lefties over the past four years ranks 18th among Major League hitters. Over the same stretch, Ozuna ranks 51st with an .853 OPS vs. southpaws.
One scout said Castellanos is the better overall hitter. He uses the whole field and can handle tough pitching, while Ozuna punishes pitchers’ mistakes. Ozuna stands out more for his quality of contact, according to MLB.com analyst Andrew Simon. Ozuna ranked in the 93rd percentile of MLB hitters this past season in average exit velocity and the 96th percentile in hard-hit rate.
Ozuna is also a little more patient. He averages 13.3 plate appearances per walk and 4.7 per strikeout in his career. Castellanos walks once every 15.5 plate appearances and strikes out once every 4.3. Simon also pointed out both players do not strike out a ton for modern sluggers. In 2019, the MLB strikeout rate was an all-time record 23 percent -- well above the rates for both Castellanos (21.5 percent) and Ozuna (20.8 percent).
Ozuna hit .231 with runners in scoring position last season, while Castellanos was at .243. Ozuna hit .188 with two strikes and Castellanos hit .160. The bottom line is both players are middle-of-the-order run producers, but another scout said Castellanos has more upside.
Ozuna won a Gold Glove in 2017, but did not have great defensive statistics this past season. There is more to this than metrics and analytics.
Ozuna has been a full-time left fielder for the past three seasons after switching over from center field. He would be replacing Calhoun, who has improved defensively in left, but still has more work to do. Castellanos has never played first, and the Rangers see Guzmán as a player who has the tools to be a plus defender at the position.
That may seem as if the Rangers would be better defensively in the short-term by going with Ozuna in left and Guzmán at first, but that difference could be reduced as Calhoun and Castellanos gain more experience at their respective positions. According to MLB.com analyst Mike Petriello, Castellanos showed significant improvement in right field this past season over 2018, his first season playing the position on a full-time basis. That hints at his aptitude for handling change.
Another factor is that Castellanos has more versatility, being able to play the outfield and possibly third base, if needed. Ozuna, on the other hand, may need to reverse his defensive decline or be relegated to designated hitter duty.
This is huge if either player is looking for more than a two- or three-year contract. More likely, each player wants at least four years -- and the Rangers weren’t willing to go that far with third baseman Josh Donaldson because of perceived health risks.
Ozuna played in 148 games for the Cardinals in 2018 despite dealing with right shoulder inflammation for the entire season. He underwent surgery following that campaign and deserves acknowledgment for playing despite the discomfort. Ozuna was limited to 130 games last season after missing more than a month with fractured fingers on his right hand, the result of diving back to first base on a pickoff play.
Castellanos has played at least 148 games in five of six seasons in the big leagues. The only exception was 2016, when he suffered a fractured left hand after being hit by a pitch, forcing him to miss nearly two months late in the season.
One factor to consider: Rangers outfielder/DH Shin-Soo Choo will be a free agent after the 2020 season. Ozuna might be better suited for DH duties in the long-term, but it could also be a fit for Castellanos if he doesn’t take to first base.
This is the big one. The Cardinals extended a qualifying offer to Ozuna, but he turned it down. Castellanos was traded by the Tigers to the Cubs at the Trade Deadline last season, so he was not subject to a qualifying offer.
The Rangers have been reluctant to give up Draft picks in the past few years. An exception could be made for an elite player, but it's unclear if Ozuna rises to that level for Texas.
That is almost certain to be the deciding factor in the Rangers pursuing Castellanos over Ozuna.