Montreal Canadiens defenceman Raphael Diaz is suffering from a concussion and did not dress in Wednesday's game against the rival Toronto Maple Leafs.

Head coach Michel Therrien said Diaz sustained the concussion during Monday's overtime loss to the Ottawa Senators.

Therrien said that Diaz felt fine during Tuesday's practice but it wasn't until Tuesday evening when he started to feel dizzy.

Former Maple Leaf, Tomas Kaberle, replaced Diaz in the lineup for Wednesday's contest.

On Tuesday, Therrien revealed that winger Rene Bourque will be out of action indefinitely with a concussion.

The 27-year-old Diaz has one goal and 12 assists with a plus- 5 rating through 19 games this season. In 78 career NHL games, all with the Canadiens, Diaz has four goals, 25 assists and is minus- 25.

Signed as a free agent by the Canadiens to a one-year contract in 2011, Diaz re-signed to a two-year contract last July.