Boston Celtics coach Doc Rivers said Thursday morning he has been disappointed with the performance of guard Jeff Green so far this season, indicating it’s up to both the team and player to figure out how to get him on track.

Green, who missed all of last season after heart surgery, has started the 2012 campaign off slowly. He’s averaging 7.7 points per game, but scored a total of three in his last two games combined on 1 of 12 shooting.

“I know he’s better and I know he can be better,” Rivers said Thursday morning in an interview on Boston sports radio station WEEI. “It’s gotta be some of what we’re doing and then some of what he’s doing. I have to figure out whatever we’re not doing as a staff and team right, we gotta fix that and then whatever Jeff’s not doing he’s got to fix that.“