The Avalanche hasn’t played its first preseason game yet, and new coach Patrick Roy already has decided to change his top lines.

Roy elected to swap Steve Downie and P.A. Parenteau from different lines starting with Tuesday’s practice at the Family Sports Center.

Instead of skating on a line with Matt Duchene and Ryan O’Reilly, Parenteau will play with rookie Nathan MacKinnon and Jamie McGinn, starting with Wednesday’s preseason game against the Anaheim Ducks at the Pepsi Center.

Downie will skate at right wing with Duchene and O’Reilly. In explaining the decision, Roy said the new lines balance each other.

“(Duchene) and O’Reilly, I think they love to have the puck, and P.A. loves to have the puck as well. At some point, someone’s going to have to go get that puck,” Roy said. “I think Downie brings that, and brings a lot of grit to that line. I think it’s a good mix. P.A. is a very experienced guy, and I think he will help Nathan a lot.”

Duchene and Parenteau clicked well on a line together last season, but just because aren’t on the same one going now doesn’t mean they won’t play together again at times. Roy is likely to mix his lines again, and the two figure to be on the ice together plenty on the Avs’ first power-play unit.

The other top Avs line of Paul Stastny, Gabe Landeskog and Alex Tanguay remains intact.

Wilson injured.

Avalanche defenseman Ryan Wilson, who figures to see plenty of ice time on the top four this season, will miss about two weeks with a knee injury, Roy said.

Wilson suffered the injury in Sunday’s Burgundy-White scrimmage at the Air Force Academy. Roy said the team is optimistic Wilson won’t miss any more than two weeks.

Wilson missed much of last season with ankle injuries.

Footnotes.

Goalie Semyon Varlamov will start Wednesday’s exhibition debut against Anaheim. Colorado opens the regular season against the Ducks on Oct. 2. Rookie Spencer Martin will serve as Varlamov’s backup and likely play half the game. While Duchene, O’Reilly and Downie will get the night off Wednesday, the line of Stastny, Landeskog and Tanguay will play against Anaheim.

… The Pepsi Center will unveil a new scoreboard and sound system at the game.

… Roy put players through a grueling skate at the end of practice Tuesday. He was not happy with some of his team’s play in the Burgundy-White scrimmage Sunday, saying “the decision-making wasn’t very good at times.” Overall, though, Roy said he has liked his team’s effort through. “We were 29th last year, so I guess we have to be different,” he said. “But I’ve liked what I’ve (seen) out there. We’re going to work hard. That’s the way it’s going to be every day.”

… The Avs signed defenseman Chris Bigras to a three-year, entry-level contract.

Adrian Dater: adater@denverpost.com or twitter.com/adater

DUCKS at AVALANCHE

Time: 7 p.m., Wednesday

Location: Pepsi Center

2012-13 records: Anaheim 30-12-6 (Second in Pacific Division); Colorado 16-25-7 (Fifth in Northwest Division)

TV: None

Radio: 950 AM





