Penguins captain Sidney Crosby is dazed after taking a hard hit from Capitals defenseman Matt Niskanen during the first period of Game 3. (Gene J. Puskar/Associated Press)

The lasting images from Monday night’s game, at least from the Pittsburgh Penguins’ perspective, may be captain Sidney Crosby getting cross-checked by Washington Capitals defenseman Matt Niskanen, Crosby lying on the ice and then, in a moment that could echo throughout the rest of this Eastern Conference semifinal series, Crosby hobbling into the locker room and out of sight.

After the game, Penguins Coach Mike Sullivan said there was no update on Crosby and the center would be evaluated later Monday night. So, at least right away, the Penguins were unsure when their star player will return to the ice and what exactly that sequence will mean moving forward.

“You know I really don’t have . . . ” Sullivan said when asked what he thought of Niskanen’s hit. “I’d rather not share my opinion on it.”

Niskanen, who played for the Penguins for 3½ seasons, rumbled into Crosby, stick high, 5:24 into Game 3. The hit came just after Alex Ovechkin’s stick connected with the top of Crosby’s helmet as the Penguins star stumbled past the crease. Crosby was face-down on the ice until a trainer got to him. Niskanen was given a major penalty and a game misconduct. The Capitals eventually won, 3-2, in overtime to halve the Penguins’ series lead to 2-1, but Crosby’s status will have a heavy bearing on the rest of the series.

Crosby had two goals and two assists in the first two games against the Capitals and 44 goals and 45 assists in the regular season. Sullivan would not confirm whether it is a potential head injury or a lower-body injury — it seemed that Crosby’s left leg twisted awkwardly as he went to the ice. All the Penguins know is that they had to play more than 58 minutes without Crosby, and that they may need to play without him again.

“It’s obviously gut-wrenching,” Penguins forward Chris Kunitz said of seeing Crosby go down. “You know it’s the best player in the world playing in his prime. He’s just dominating games. It’s one of those things that you look at it once you see what actually happened.

“I think the next thing is watching how deliberate it was watching when the guy cross-checks him in the face. I thought all that was kind of out of this league, but I guess not.”

Kunitz was not the only player who, unlike his coach, offered an opinion on Niskanen’s hit. When asked what he made of the hit, Penguins center Nick Bonino said, “Just what we saw, he hits him straight in the head with his fist or stick.”

Other Penguins said they did not see a replay yet or had nothing to share. Penguins rookie forward Jake Guentzel did not think Niskanen had any malicious intent with the hit, and Capitals Coach Barry Trotz maintained that it was a “hockey play.”

On Monday night, a source said the league was leaning toward Niskanen not facing any additional discipline for the cross-check. A final decision on that will be made Tuesday.

“Absolutely not. It wasn’t intentional,” Niskanen said when asked if he meant to cross-check Crosby. “I’ve seen the replay. In super slow-mo, it looks really bad. I caught him high. He’s coming across trying to score. As he’s doing that, he’s getting lower and lower, and when it’s happening that fast, you know, my stick and his head collided. I wasn’t extending trying to hit him in the head. It happened quickly.”

It also happened to Crosby, which is why speculation will endure and so much hinges on whether he returns.

The Penguins constructed a de facto top line of Kunitz, Evgeni Malkin and Phil Kessel in Crosby’s absence. They hung in an ugly game and scored two six-on-five goals at the end of regulation to force overtime. They still lead 2-1 and have a lot of experience plugging large holes in their lineup.

But a Crosby-sized hole would be a lot to deal with this time of year, even if the Capitals have been spotty and nearly collapsed in Game 3. Now the Penguins wait for word from their team doctors. An update could come after they practice Tuesday afternoon. And then the series, either reshaped or returned to its original form, will proceed from there.

“I think this group has so much character and talent that we’re able to endure the injuries that we have,” Sullivan said. “We’ve done it all year long and we did it again tonight, and we’ll continue to do it.”

Isabelle Khurshudyan contributed to this report.