Klopas will sit out Saturday's game against Real Salt Lake. Assistant coach Mauro Biello usually takes over when the head coach is suspended.
The league's disciplinary committee ruled that Klopas violated a policy on "entering the field/leaving the bench area in the 90th minute of Montreal’s match against the Portland Timbers" last Saturday. Portland won the game 2-1.
As his team prepared for a free kick near the Impact bench area, Klopas briefly stepped over the sideline to kick the ball back to his player before it rolled out of bounds.
It is the second suspension this season for the Impact's second-year coach. Klopas missed the second leg of the CONCACAF Champions League semifinals against Alajuelense for a similar infraction.
He was also suspended for a game in Chicago against his former team last season.
Having a coach suspended is nothing new for the Impact. Klopas's predecessor, Marco Schallibaum, was suspended four times for a total of five games in 2013.