Golden State Warriors star guard Klay Thompson has suffered a season-ending Achilles tendon tear, a source told ESPN's Adrian Wojnarowski.

Thompson suffered a right leg injury during a workout Wednesday in Southern California, the team announced. He underwent an MRI on Thursday morning.

Thompson was playing with several NBA players in Los Angeles and felt pain in the calf area when he landed on his leg, sources told ESPN's Ramona Shelburne.

Warriors general manager Bob Myers said late Wednesday night that coach Steve Kerr and members of the Warriors training staff were expected to fly to Los Angeles to be there for Thompson.

"It's one of those deals where you don't really know until you know," Myers said during a post-draft conference call with reporters. "You can be hopeful, you can be concerned. I'm probably all those combined, and until we know more tomorrow, I'll just hope for good news."

Thompson, 30, missed all of last season after tearing the ACL in his left knee during Game 6 of the 2019 NBA Finals against the Toronto Raptors. The Warriors were optimistic that Thompson, who has spent more than a year rehabbing the injury, would come back at full strength for the 2020-21 season.

ESPN's Nick Friedell contributed to this report.