DENVER -- The St. Louis Blues cruised to a 5-1 win against the Colorado Avalanche at Pepsi Center on Sunday, but lost goalie Jake Allen to an undisclosed injury in the first period.
Allen stopped all 11 shots he faced, and was replaced by Anders Nilsson to begin the second period.
Blues coach Ken Hitchcock said he didn't know what the injury is or how serious it is.
"I'm not sure," he said. "We'll know a little bit more on Jake [Monday]. Hopefully it's day to day."
Video: STL@COL: Pietrangelo tallies off a faceoff win
Nilsson, who had 19 saves, said he noticed that Allen "stayed down a little longer" after making a save late in the period.
"But I didn't know what happened," he said. "I was a little surprised when they said he's not going in the second. Hopefully it's not too bad and he can be on the ice real soon."
The Blues (47-23-9), who have a clinched a berth in the Stanley Cup Playoffs, are in second place in the Central Division, two points behind the Dallas Stars with three games to play, one more than the Stars, who lost 3-1 Sunday to the Anaheim Ducks.
The Blues took a 3-0 lead in the first period on goals by David Backes, Magnus Paajarvi and Colton Parayko. Alex Pietrangelo made it 4-0 at 3:26 of the second period.
Video: STL@COL: Paajarvi chips the puck over Varlamov's pad
"The biggest thing is worrying about ourselves," Pietrangelo said. "We know if we play the way we can, we're going to put ourselves in a good position."
The Avalanche (39-36-4), who have lost three games in a row and five of their past six, remained five points behind the Minnesota Wild for the second wild card into the playoffs from the Western Conference with three games remaining, one more than the Wild.
Colorado remained alive for a playoff berth because the Wild lost 5-1 Sunday to the Winnipeg Jets.
"It's disappointing not to come away with two (points) there and gain a little ground," said Avalanche center Matt Duchene, who scored his 30th goal of the season at 15:46 of the third period. "The good news is we're still in it, we have a chance here. We have to regroup and go for it. We're working hard, but we have to be smarter. We're shooting ourselves in the foot too much.
Video: STL@COL: Parayko beats Varlamov through a screen
"We're fighting for our lives. We're going to have to show what kind of mental fortitude we have, and right now it's not as good as it could be and we need to be better."
Avalanche goalie Calvin Pickard (23 saves) replaced Semyon Varlamov to begin the second period after Varlamov allowed three goals on 14 shots in the first.
Backes scored at 5:30 of the first period with Avalanche captain Gabriel Landeskog in the penalty box for delay of game. After Allen made a save against John Mitchell, Kevin Shattenkirk got the puck to Backes, who skated down right wing into the Colorado end on a 2-on-1 rush with Vladimir Tarasenko. Backes passed to Tarasenko, moved into the left circle and accepted a return pass before scoring into a half-open net for his 21st goal.
Paajarvi was on the doorstep when he took a couple of whacks at the puck and banged it inside the left post at 8:56 for his third goal and first since Dec. 21.
Parayko's scored at 16:09. Alexander Steen was behind the net when he passed to Parayko at the right point for a one-timer behind Varlamov for his ninth goal.
Video: STL@COL: Backes opens the scoring with a PPG
"We really started the game well," Hitchcock said. "We put a lot of pressure on them and made them make mistakes. We scored goals because of it. I like the way we played the first half of the game. We really played well. I liked the way we played in the first period. It was sound, it was sending the other team a message and it was a good sign."
The Avalanche made it 4-1 when Duchene tipped in Mikkel Boedker's shot to become the first Colorado player to score 30 goals since 2006-07 when Joe Sakic had 36 and Milan Hejduk had 35.
Troy Brouwer scored into an empty net with 2:55 remaining for his 17th goal.
"For some reason we're in a funk at home and we're struggling winning some hockey games," Roy said. "It's not the type of hockey we want to play. I think we need to learn how to win, we need to change the mindset. I think we have a losing mindset right now.
"I think we have to find ways to believe more in ourselves. Sometimes things are not going to go our way. We might give up one goal, we might give up two goals. Who cares? We need to play our game."
Video: Blues cruise past Avalanche but lose Allen to injury