Semin was injured Saturday during the Hurricanes' 4-2 loss to the St. Louis Blues on a hit by Blues defenseman Alex Pietrangelo. Semin returned to the ice briefly after the hit, but left the game for good in the second period.
The 29-year-old was out of the lineup Monday against the Boston Bruins.
Semin, who was second on the Hurricanes with 44 points last season, has three goals and six assists in 20 games this season.
It was a different game in the past, that's for sure. It's not exactly what I was expecting but I think the experience paid off for a lot of our guys that realized what it takes in a Game 7. Realistically the effort we put forward, we might not even had to put 60 [minutes], but we just couldn't get a couple bounces to go our way and we just kept pushing.
— Capitals goaltender Braden Holtby on Washington's play in Game 7 vs. the Islanders