Montembeault allowed five goals on 30 shots in Monday's 6-3 loss to the Penguins.
Montembeault had been a wall through his first two starts, giving up one goal on 73 shots, but he was more of a window than a wall Monday. The Habs managed to hang in after falling behind, 2-0, but Pittsburgh scored three times in the third period, twice against Montembeault before they added an empty-netter. The Canadiens next play Thursday at home against Los Angeles.