SANTA CLARA -- Arik Armstead is expected to be ready for the start of the team’s offseason program in the spring after he recovers from Tuesday’s surgery on his injured left shoulder.
The 49ers’ 2015 first-round draft pick was placed on injured reserve last week, ending a season in which he often was forced to the sideline with an ailing left shoulder that began bothering him in training camp.
The specific injury has yet to be revealed, but a source said that the shoulder continued to “sublux,” or partially separate, after he initially hurt it in a practice on Aug. 7. That explains the shoulder harness Armstead wore during the season and the wide range of snaps he would play from game to game.
The source did not want to be identified because he does not have authority to speak on the matter.
Defensive coordinator Jim O’Neil said that injury sidetracked what was shaping up to be a special season for Armstead.
“I think everybody saw the play-making ability he had in the run and pass game,” O’Neil said. “And then when the shoulder (injury occurred) and he lost strength in that, he wasn’t the same player. I do credit the kid for trying to fight through it. He tried to play to the best of his ability to help his teammates out. But he clearly wasn’t the guy that he was in spring and in training camp that, as a staff, we felt would be Pro-Bowl, All-Pro-type difference maker for our defense.”
Armstead posted an Instagram photo Tuesday of him in a surgical gown while also noting it was his 23rd birthday.