Ovechkin was taken to the hospital, Russian coach Oleg Znarok said after the game. Ovechkin appeared to sustain the injury to his right leg in the third period of Russia's 3-0 win over Germany. He required assistance off the ice and Znarok said he could not "share any information now" about the injury, and that more details would be disclosed after Ovechkin was examined.
"We are aware that Alex Ovechkin sustained an injury during today's game versus Germany," the Capitals said in a statement. "Our medical staff is working with Ovechkin and Team Russia to gather additional information at this time."
Ovechkin collided with forward Marcus Kink midway through the third period and stayed on the ice for several minutes before he needed assistance to leave the ice. He struggled to put weight on his right leg and did not return to the game.
Ovechkin has scored three goals and added six assists for Russia in the tournament.
"It's an unfortunate incident and we hope he's OK," Germany coach Pat Cortina said. "He's a great player and a great ambassador for the game of ice hockey. We need players like that and hopefully he will be fine and we'll see him back on the ice soon."
Russia is waiting for the arrival of another star forward, Evgeni Malkin, who agreed to join the team at the worlds after his Pittsburgh Penguins were eliminated from the NHL playoffs. Malkin could be available for Tuesday's final group-stage game against Belarus.
Information from The Associated Press was used in this report.