Memphis Grizzlies center Steven Adams will undergo season-ending knee surgery, the team announced Sunday.

Adams hasn't played since sustaining a season-ending PCL injury on Jan. 22. The injury cost him the final 36 games of last season and will now sideline him for all of 2023-24.

Adams underwent a stem-cell injection in March with a plan to be re-evaluated in four weeks. The injury ended up lingering through the playoffs and offseason. The Grizzlies stated in Sunday's announcement that rehabilitation “did not resolve ongoing knee instability.” They did not provide further details of what's gone wrong in Adams' recovery.

The loss is a difficult blow for Adams and a Grizzlies team looking to build off last season's second-place finish in the West. They'll now face the season without their starting center and All-Star guard Ja Morant, who is suspended for the first 25 games after multiple off-court incidents involving guns.

Adams, 30, averaged 8.6 points, a team-best 11.5 rebounds, 2.3 assists and 1.1 blocks in 42 games last season. Backup Xavier Tillman projects to start in his place with All-Star forward/center Jaren Jackson Jr. likely seeing more time in the post.