The Capitals were on the power play in the first period when Stepan carried the puck into the Capitals zone with Ovechkin and Erat in hot pursuit. As Erat reached under Stepan's arm, his wrist appeared to get pinned by Stepan right as Ovechkin arrived from the side to deliver a check.
All three hit the ice in a yard sale of bodies, with Erat clutching his wrist as he lay in the Capitals net:
His wrist, it did not look good.
Erat left the game and did not return.
To add insult to this very literal injury, both Erat and Ovechkin received penalties on the play, negating the Capitals power play.
Acquired at the trade deadline from the Nashville Predators, Erat had become a key forward for the Capitals, logging 17:48 of ice time per game and being used on both the power play and penalty kill during this series.