The decision was made after Duchene took part in his second full morning skate in three days and met with the team doctor.
Avalanche coach Patrick Roy said earlier this month that he would be "very, very suprised" if Duchene didn't miss the entire first-round series.
Duchene injured his MCL in March against the San Jose Sharks and was expected to miss four weeks. He had 23 goals and a team-leading 70 points in 70 games this season. He missed three games in November after sustaining an oblique injury against Florida.
Information from ESPN.com's Pierre LeBrun and Craig Custance was used in this report.