Updated

Boston Bruins forward Nathan Horton has reportedly been playing with a shoulder injury that will eventually require surgery.

Horton left Game 1 of the Stanley Cup Finals on Wednesday during the first overtime period after jostling with Chicago defenseman Niklas Hjalmarsson in front of the net. He skated off the ice and didn't return as the Bruins dropped the opener in triple-overtime.

The Bruins termed it an upper body injury and coach Claude Julien on Thursday said Horton is day-to-day. Game 2 is set for Saturday in Chicago.

According to WEEI-FM in Boston, Horton has been bothered by a left shoulder subluxation, an injury he first sustained during an April 20 fight with Pittsburgh's Jarome Iginla. He missed the final five games of the regular season before returning for the playoffs.

The radio station cited a source as saying Horton has been taking injections to deal with the pain. He apparently had the shoulder popped back into place on Wednesday, but was unable to return because of the pain.

Despite the injury, Horton has not missed a game this postseason and is Boston's second-leading scorer in the playoffs with 18 points. He has seven goals and 11 assists in 17 games.