The NHL said Rolston was fined for "player selection and team conduct" after putting six-foot-eight enforcer John Scott on the ice after a fight between Toronto's Jamie Devane and Buffalo's Corey Tropp. In its news release announcing the fine, the league said Scott "initiated an altercation" with Leafs forward Phil Kessel.
The amount of Rolston's fine was not disclosed.
Because the Leafs were at home, coach Randy Carlyle had the last change. He said he put Kessel's line on the ice to diffuse the situation after Devane and Tropp fought.
A total of 211 penalty minutes were assessed from the brawl, which took place midway through the third period. Toronto right-winger David Clarkson was given a game misconduct and automatically suspended 10 regular-season games for leaving the bench to enter an altercation.
Kessel had a disciplinary hearing with the league Tuesday to discuss his slashes on Scott.