Thomas (upper body) will miss Thursday's tilt against San Jose, according to Lou Korac of NHL.com.
Thomas was injured Tuesday against Washington when he was hit by Pierre-Luc Dubois, who received a match penalty for his misdeed. Thomas has 16 goals and 30 assists in 53 games this season, including nine points on the power play. He is day-to-day at this time and could return as early as Saturday in Toronto. Dalibor Dvorsky will move up to the top line, replacing Thomas.