The MLS disciplinary committee has announced that it is suspending LA Galaxy manger Bruce Arena for one match. During stoppage time in the match against Portland, Arena left the technical arena to argue Robbie Keane's set piece goal was not offside. Per league policy this results in an automatic one match suspension.
Bruce Arena will not be allowed on the sideline or in the locker room for the Sunday matchup against Chivas USA.
Watching the replay again it's surprising that LA didn't get penalised for mass confrontation as well. Robbie Keane and Landon Donovan immediately crowd the referee, and then the camera cuts to Bruce Arena well past the touch line. It happens often in the melee after a significant goal, but with so many on LA losing their cool after the goal was ruled offside MLS likely felt they had to send a message.
It also highlights some other behaviors on the play. Keane clearly starts the play offside which is probably the point at which the official on the sideline took notice of him. Pure speculation, but it's worth thinking about if Keane would have been called for such a close offside had he started the play onside.