Castellanos was hit in the wrist by a pitch last week, causing him to miss multiple games. On Friday morning, he told Caleb Noe of WCPO-TV he had suffered a small fracture.
The 29-year-old is having a career year, hitting a National League-leading .329 with 18 homers, 59 RBI, 59 runs and a .965 OPS in 86 games. Those numbers led to his first All-Star Game appearance.
"Watching All-Star Games on TV as little kids, to be here and be a part of it? Dope," he told reporters.
Castellanos could always leave the park—he exceeded 20 home runs in each of the 2017-19 seasons and likely would have done so last year in a full season after posting 14 dingers in 60 games. However, his batting average and ability to get on base (.383 OBP) have dramatically improved this season.
The Reds have profited. Castellanos was joined by Jesse Winker on the All-Star team, and that pair have helped keep the Reds in the postseason conversation. Any injury to Castellanos, however much time he misses, is a major blow for Cincy.
For as long as Castellanos is out, Winker will be the centerpiece of the Cincinnati offense with his .292 average, 19 home runs and 52 RBI.
Joey Votto, Jonathan India, Eugenio Suarez and Tyler Naquin will be looked upon to pick up the slack as well.
Aristides Aquino and Shogo Akiyama will likely see increased playing time until Castellanos returns. Aquino is hitting .246 with six home runs and nine RBI, while Akiyama is hitting .196 with no homers and eight RBI.
The Reds are second in the NL Central at 49-47 and trail the Milwaukee Brewers by 6.5 games.