Blackhawks coach Jeremy Colliton said the 33-year-old goalie will be under concussion protocol and doesn't have a timetable for his return.
Chicago was leading 3-2 when the injury occurred at 18:30. After Crawford made a save on Sharks forward Logan Couture, San Jose forward Evander Kane collided with Blackhawks forward Dylan Strome, who crashed into his goalie. Kane received a penalty for goaltender interference on the play.
"He's probably the guy that's worked the hardest and held us in the most over the season," Blackhawks defenseman Connor Murphy said. "So that's never a good sign."
"[Crawford is] such a big part of our team and to lose him, it's not good. You just feel for him because [in] a game like that, we left our goalies hung out to dry. And for them to take guys crashing on him is not even fair either."
Colliton said he wasn't sure Kane could have avoided the play.
"Yeah, I don't see that," Colliton said. "Honestly, I haven't looked for that and for me, the focus is on the goaltender. He's hurt, so that's unfortunate."
Cam Ward replaced Crawford and allowed five goals on 35 shots.
"When you're out there it doesn't have to much of an effect on if the goalie changes or whatever happens," Strome said. "We were just trying to continue to battle and that's what happens sometimes."
Crawford, who entered the game 6-14-2 with a 3.23 goals-against average and .903 save percentage, missed the final 47 games last season, and the first five games this season, while dealing with the remaining symptoms from a concussion.
"I mean you never want to see that, but we have to keep playing," Blackhawks defenseman Duncan Keith said. "It's just one of those things that hopefully he's back. I don't know what happened, but nothing should change."
