Rusney Castillo will miss at least one week with a left oblique strain.
Rusney Castillo got his left side checked out by team doctors on Wednesday morning and said it's "nothing serious."
Rusney Castillo felt some pain in his left side in his final at-bat of Tuesday's spring game.
Red Sox manager John Farrell said Sunday that Rusney Castillo and Mookie Betts are "going to get equal playing time" during spring training.
Rusney Castillo batted .405 in 10 games with Criollos de Caguas of the Puerto Rico Winter League.
Rusney Castillo will travel to Puerto Rico this week to begin playing winter league ball, the team announced Tuesday.
Rusney Castillo (thumb) has been cleared to play in the Puerto Rican Winter League.
Red Sox general manager Ben Cherington said Wednesday that the team has yet to decide whether Rusney Castillo (thumb) will play again this winter.
Red Sox general manager Ben Cherington said Tuesday that Rusney Castillo (thumb) "essentially is healed."
Rusney Castillo has been diagnosed with a strained adductor muscle in his right thumb.
Rusney Castillo (hand, thumb) will not play again in the Arizona Fall League.
Rusney Castillo (hand, thumb) is on the roster for Los Criollos de Caguas in the Puerto Rican Winter League.
Rusney Castillo (hand, thumb) is unlikely to return to action in the Arizona Fall League.
Rusney Castillo suffered a minor hand injury Monday in the Arizona Fall League.