Russian hockey officials announced Thursday that Capitals superstar Alex Ovechkin played through injury before Washington was eliminated from the NHL playoffs in the second round by the Pittsburgh Penguins.

Ovechkin finished the playoffs dealing with a lower-body injury that required pain-numbing injections, the Russian Hockey Federation said in noting that Ovechkin would not be able to play for Russia at the world championships in Europe because of it.

UPDATE: Later Thursday, Russian head coach Oleg Znarok said Ovechkin played through knee and hamstring injuries during the playoffs. 

Ovechkin never let on that he was playing hurt. He had five goals and three assists in 13 playoff games as the Capitals flamed out again, eliminated in seven games by the defending Stanley Cup-champion Penguins . Coach Barry Trotz is expected to address all team injuries at his post-season news conference Friday.

It was not immediately clear when Ovechkin was injured or how severely. He did not miss a game but briefly left late in the first period Game 5 of the first round after clutching his knee following a hit from Toronto's Nazem Kadri, returning for the start of the second.

Ovechkin said after that game April 21 he was not worried about his knee and "just needed a little break." NHL teams are not required to disclose injury details, typically referring to them only as upper- or lower-body problems, which made Ottawa captain Erik Karlsson's admission of playing with two hairline fractures in one of his feet so stunning as it came while the Senators were still playing.

An odd lineup midway through the second round against Pittsburgh could make more sense now. Trotz moved Ovechkin to the third line before Game 5, slightly reducing his ice time and calling it a chance to spread out his offence and not a demotion. After the Capitals were eliminated on Wednesday night and Ovechkin played the seventh-most of any forward at even strength, Trotz demurred on a question about his 31-year-old captain's play.

"Emotionally right now, I don't want to answer that question," Trotz said after the 2-0 loss. "We win and lose as a team. That's probably my best answer right now. Emotionally, I don't think I want to answer that question at all."

Ovechkin has played at the world championships 12 previous times, including in 2013 when he finished the playoffs with a hairline fracture in his foot.

Kuznetsov, Orlov to join Russia

Capitals forward Evgeni Kuznetsov and defenceman Dmitry Orlov will join Russia for the World Hockey Championships. 

Kuznetsov, 24, had 19 goals and 40 assists in 82 regular season games for the Caps to go along with five goals and five assists in 13 playoff games this season. Orlov, 25, had six goals and 27 assists in 82 regular season games. The blue liner added three assists in 13 games during the Capitals' playoff run.

Kuznetsov and Orlov are restricted free agents who need NHL contracts for next season, something that often leads players to decline an invitation to play for their national team.

Russia is off to a strong start so far in this year's World Hockey Championship, with three regulation wins and one overtime win for a total of eight points. They currently lead Group A ahead of USA and Latvia.