The St. Louis Blues placed forward Alex Steen on injured reserve with a concussion Saturday.
Steen has not played since he left a game against the Edmonton Oilers a week ago with an upper body injury. Steen is out indefinitely, general manager Doug Armstrong said in a statement.
Steen leads the team with 38 points and is second in the NHL with 24 goals in 35 games.
In his ninth season, Steen has 147 goals, 194 assists and 248 penalty minutes in 572 NHL games with the Toronto Maple Leafs and Blues.
He signed a three-year, $17.4 million contract extension earlier this month.