The Russian coach at the 2017 IIHF World Championships told the press, in Russian, that Alex Ovechkin was too hurt to join the team.  Later clarification that it was a leg injury led many to speculate it stemmed from the hit by the Toronto Maple Leafs Nazem Kadri in Game 5 of the first round of the playoffs.

Ovechkin stayed down on the ice after this collision, and needed help off the ice.  He came back very quickly, and seemed fine. By the next game, everyone had forgotten and assumed he was fine.  At the time, there were dark accusations that Ovechkin had somehow managed to fake being injured on the hit and then took himself out of the game for the ensuing power play, which never made much sense.

When do dark accusations against Ovechkin make sense?

So he played on an injury, as almost everyone in the playoffs does.  And he was faking all along — faking being okay.