To make room for Thornton on the roster, centre Dylan Gambrell was assigned to the San Jose Barracuda of the AHL.
Thornton, 39, has missed the last nine games with an infection in his right knee. In two games this season he has one assist and a plus-1 rating.
“I’m still going to be on some antibiotics, but it looks like (the infection) is on its way out,” Thornton said after practice Tuesday, according to The Mercury News. “I’ll probably be a little bit tired the first game, but I’ll be fine.”