Duchene didn't practice Saturday, and coach Jared Bednar said he would be evaluated on a day-to-day basis.
"I guess he got hit and it kind of caught him in the eye," Bednar said. "So he had some blurry vision. So that's why he was off getting evaluated, and then he didn't feel so good. [The training staff] kept him out and this morning he was better, but not 100 percent, so he didn't skate today.
"He's got concussion-like symptoms, but [Sunday] will be a big day, see how he comes in and then we can kind of go from there. He's day to day at this point, so we just have to see if he feels good and can skate, and then he'll probably have to do another test to see if he's able to play or not."
Bednar said he didn't think the NHL's spotter system regarding concussion precautions came into play Friday.
"I don't think so," Bednar said. "It was pretty obvious. He was driving the net and I think Trouba caught him up high with the stick and part of his hand, whatever it was. He came off right away. He played a couple more shifts, I think, and his [vision] was kind of messed up, so he was going to go off at the intermission and get evaluated.
"[Trouba] gets caught coming straight at him and kind of jukes him, and I think it was incidental contact. He was going one way and he clipped him. There's nothing intentional there in my mind."
Duchene was centering a line with left wing Mikko Rantanen and right wing Nathan MacKinnon. MacKinnon moved to center after the injury with Gabriel Landeskog on the left side and Rantanen on the right. The three practiced together Saturday and are expected to remain that way against the Bruins.
"You can't replace him," MacKinnon said. "He's one of our top players, he's leading our team in goals and points, he's been really good this season. It'll be tough, but we have to fill the void. Me and Mikko have been really good together this year and I've been playing with [Landeskog] the last few years. I feel comfortable with both those guys."
The Avalanche on Saturday called up forward A.J. Greer, who has four goals and 10 assists in 13 games with San Antonio of the American Hockey League. The 19-year-old was a second-round pick (No. 39) in the 2015 NHL Draft.
Colorado was carrying one extra forward, and Blake Comeau has missed three games because of a groin injury. Comeau practiced Saturday, but Bednar said he didn't think he is ready to play against Boston.
"This groin thing's been going back and forth for him," Bednar said. "So I think the plan for him is to have three or four good days of skating and when he feels real strong and explosive, then get him in the game, so something's not acting up on him again. We want him at 100 percent because he's a guy who can help us with his speed, penalty killing, physicality."
