The top free-agent right fielder on this winter's market, Castellanos was excellent in 2019, with a .289/.337/.525 slash line to go along with 27 home runs and a major league leading 58 doubles. He cranked things up after a midseason trade to the Cubs, hitting .321/.356/.646 in 51 games on the North Side.
The White Sox are certainly familiar after Castellanos tormented them for more than half a decade with the division-rival Detroit Tigers. In recent seasons, he wore South Side pitching out, with a 1.039 OPS, five homers and 20 RBIs in 19 games during the 2018 season and an even better 1.132 OPS, two homers and eight RBIs in just eight games in 2019.
He's also particularly feasted at Guaranteed Rate Field, where he hit .316/.381/.579 in 2018 and an even better .417/.462/.792 in 2019.
Castellanos' bat is not a question. It would be just the kind of thing the White Sox would like to add to the middle of their lineup. Word from sports betting expert Sam Panayotovich that they're "strongly pursuing" Castellanos shouldn't come as too much of a surprise, either. Rick Hahn included right field on his offseason to-do list and has long stated that adding an impact player from outside the organization is one of the goals of his rebuilding effort.
But what about the glove?
The knock on Castellanos has long been his defense, and at least one of the metrics used to measure defense backs those concerns up. His minus-nine Defensive Runs Saved in 2019 were better than only three other right fielders in the majors.
To many, that might not strike as a big deal. You might be thinking: "So the glove isn't as good as the bat. Have you seen how good the bat is?"
That's not at all a ridiculous opinion to have. But the White Sox need to take the rest of their outfield into account. Eloy Jimenez very much looked like a work in progress in left field during his rookie season. Luis Robert has received positive reviews for his defensive ability as a minor league center fielder, but he'll be getting just his first taste of the majors in 2020. Saddling him with both Jimenez and Castellanos on either side could potentially have some negative impact on his development. It's unknown what the White Sox think about that.
The reputation is enough that former big league general manager Jim Bowden wrote in regard to Castellanos just the other day at The Athletic that "he'll need to sign with a team that has plus defenders at the other two spots." The White Sox will not fit into that category unless Jimenez makes a big leap from his rookie to sophomore seasons.
None of that is to suggest, however, that the White Sox should stay away from Castellanos. The bat is just the kind of thing they're looking for, and the fact that he's only 27 lines up nicely with Hahn's plans for long-term contention. He's also got a reputation as a great clubhouse guy, with the term "leader" being thrown around during his half season with the Cubs.
But the defensive ability, coupled with his agent being Scott Boras, could provide some hurdles. Would Castellanos be interested in DH-ing? Not many under-30 players looking to score huge multi-year contracts are. But that's a hole the White Sox need to fill, as well.
Considering Hahn's ongoing efforts to bring in a big name and help vault his rebuilding project into overdrive, we should expect to hear plenty about the White Sox being in pursuit of some of the biggest names on the free-agent market. Castellanos included.