The forward hasn't played since March 28. He scored 14 points (seven goals, seven assists) in 33 games this season.
"He was trying to come back from that injury, he practiced two days ago and felt pretty good through most of it," Red Wings coach Jeff Blashill said Friday. "Felt a twinge at the end, and in the end, it's a situation where we expect him to miss the rest of the season."
Ryan missed two games (March 16 and 18) with an upper-body injury and has been dealing with a back injury.
"He was making progress, I think he thought it was going in the right direction," Blashill said. "Originally, we thought it was a minor thing, and as it's gone, again, as you try to work your way back, sometimes you have setbacks. He had a setback, and because of that, he's just not going to be able to do it."
Ryan signed a one-year contract with the Red Wings on Oct. 9 and can become an unrestricted free agent after the season.
"I think Bobby came in, did a really good job, obviously scored early," Blashill said. "Again, he's had a nagging back injury through parts of the year and those are the ones that don't necessarily go away. So, it probably hurt his ability to just keep rolling. Obviously scoring is one of those things that fluctuates. I liked having him on our team, he made our team better, and he was a good example for our young guys.
Selected by the Anaheim Ducks with the No. 2 pick in the 2005 NHL Draft, Ryan has scored 569 points (261 goals, 308 assists) in 866 games with the Red Wings, Ottawa Senators and Ducks and 32 points (18 goals, 14 assists) in 51 Stanley Cup Playoff games.
"Bobby's a great person, he's been a good leader in our room, I think he's been a good example and a guy who can score goals," Blashill said. "So, we'll miss lots of what Bobby brings and I feel bad for him that his season's cut short."
NHL.com staff writer Tracey Myers contributed to this report
