"It's a big loss, but we can't look back anymore," Rantanen said. "It's happened and now a lot of guys have to fill some spots and take bigger roles. There's guys that can do that and we're going to go with what we have. ... He's our captain, a key player and a key leader. It's time for other guys to step up."
Bednar said Derick Brassard would take Landeskog's spot on the top line with MacKinnon at center when the Avalanche host the Buffalo Sabres at Pepsi Center on Saturday (3 p.m. ET; ALT, MSG-B, ESPN+, NHL.TV). J.T. Compher was the right wing on that line at practice.
"Every time we miss a guy, you're looking for other guys that can possibly step in and do that job or you have to rearrange things," Bednar said. "We're going to try and rearrange some things and see if we can't find some magic with guys split up on different lines and see if guys can elevate their game.
"It's going to be a great opportunity for some guys. We need some guys to step up now and elevate their game. ... Everyone will get a little more opportunity. We'll just have to fill in by committee."
NHL.com correspondent Rick Sadowski contributed to this report