Boston Bruins coach Claude Julien said Thursday that forward Nathan Horton is day-to-day with an apparent upper-body injury.
Horton left the Bruins' 4-3 triple overtime loss to the Chicago Blackhawks on Wednesday in the first overtime period.
"Fingers crossed at the end of the day that he's back for next game," Julien said according to the Bruins' official Twitter feed.
He logged 20:55 in ice-time on Wednesday night before leaving the game, assisting on Milan Lucic's opening goal.
Horton has seven goals and 11 assists in the playoffs for the Bruins.