Lehtinen started Saturday night's game against the Detroit Red Wings but didn't finish. He played about six minutes in the first period and just nine seconds in the second.
He has four goals and four assists in the playoffs and had 37 points in 48 regular-season games.
The Red Wings were without right winger Johan Franzen for the second consecutive game with concussion-like symptoms. Franzen has had recurring headaches since early in the previous series against Colorado.