Crosby has six points (two goals, four assists) in four games at the Olympics.
He appeared to sustain his injury on a hit from Radko Gudas at the red line between the benches at 4:55 of the second period. His legs appeared to split when Gudas toppled over him. Crosby was favoring his right leg as he got up a bit hobbled but stayed on the ice.
Thirteen seconds later, Crosby was hit by Martin Necas and Gudas along the boards near Canada's bench. He stayed upright and took two strides toward the middle of Canada's offensive zone before pulling up and circling to go to the bench.
He stayed on the bench for about a minute while getting looked at by Team Canada medical staff, before leaving to go to the dressing room with 13:55 remaining in the period and Czechia leading 2-1.
Cooper said Team Canada knew something had to really be wrong because Crosby rarely sustains an injury in a game that requires him to leave.
Nick Suzuki took Crosby's place on his line with Mitch Marner and Mark Stone. Macklin Celebrini replaced him on Canada's first power-play unit.
"He's probably one of the toughest guys in the whole league," Suzuki said. "Seeing him off the ice the way he takes care of himself, all the treatment, all the mobility work, always taking care of his body to prepare for the next day, you can see why he's played for so long and at such a high level."
Suzuki said he recognized the responsibility of replacing Crosby, especially to center what he called Canada's "most consistent line" at 5-on-5.
"When I got put there, it felt pretty easy for a centerman to have two wingers like that," Suzuki said of Marner and Stone. "We'll see what happens tomorrow. Hopefully we can have Sid back, but I think I can find a way to play with anybody."
Despite the injury, Crosby addressed the team in between the second and third periods, delivering a message to "Go get it, boys," Cooper said following the game.
"He's Sidney Crosby, he's going to have a big influence no matter what," Canada center Connor McDavid said. "In the lineup, not in the lineup, he's going to have a big influence. That's what he does."
Crosby's presence will remain significant for Team Canada even if he can't play Friday, but Cooper said he's less concerned about not having his on-ice leadership Friday because he has seen other players become more vocal than they were at the 4 Nations Face-Off, where Canada won the championship.
"I've watched it grow," Cooper said. "You get to that 4 Nations tournament and I think everybody was looking to Sid in that tournament. I think guys like (Drew) Doughty and (Brad) Marchand, the guys that have been there for a number of years, were the more vocal guys that stepped up, but I'm seeing much more out of the group now, especially Connor. Not that he wasn't comfortable, but I think there was a lot of uncertainty especially because we hadn't seen best-on-best and this group hadn't been together for so long. In this tournament, he's been fabulous."
