The Colorado Avalanche only have three full-time defensemen returning from last season: Erik Johnson, Tyson Barrie and Francois Beauchemin. After those three defensemen, there are three others that played a combined 59 games for the Avalanche last season: Chris Bigras, Nikita Zadorov and Eric Gelinas in respective order for games played.
Then, there are two others that they picked up in free agency: Fedor Tyutin and Patrick Wiercioch, who played a combined 113 games in the NHL last season.
All-in-all, the Colorado Avalanche have six defensemen on one-way contracts, and four more on two-way contracts who could conceivably challenge for a roster spot during training camp.