Lars Eller walked into the tunnel with head athletic trainer Jason Serbus during the second period of Game Two with a lower-body ailment. He didn't come back for the third quarter. Eller's left leg was grabbed from behind as he dropped to one knee to take a shot on goal, according to the NBC Sports Washington program. He stayed down for several minutes before being helped off the ice. Eller had an MRI on Monday that revealed no broken bones but did reveal some muscle tears. He is expected to be out for at least four weeks. The Capitals announced after the game that Eller would not return to action and said he will be sidelined for 4-6 weeks. "He'll be out for a long time," Coach Barry Trotz said. "It looks like six to eight weeks." Eller, 26, has five goals and three assists in 21 games this season. Before his injury, he was enjoying a career year after scoring 30 goals last season. The Czech Republic native also represents his country in international play. He was named to the 2016 IIHF World Championship team earlier this month. With Eller out, Tom Wilson will assume more responsibility on the power play. Joel Ward and Andre Burakovsky will also see increased ice time. In other news, Defenseman Matt Niskanen missed Sunday's game because of an upper body injury.