WASHINGTON — Robert Griffin III had surgery Wednesday morning to repair a torn ligament and to determine whether there was any other damage in his ailing right knee.

A person familiar with the situation told The Associated Press that the procedure was expected to last about two hours. The person said orthopedist James Andrews planned to repair a torn lateral collateral ligament and examine the state of Griffin’s ACL.

The person spoke on condition of anonymity because the Redskins had not made an announcement about the latest details surrounding the rookie quarterback’s injury.

A torn LCL requires a rehabilitation period of several months, possibly extending into training camp and the start of next season. A torn ACL is a more severe injury, typically requiring nine to 12 months of recovery, although Minnesota Vikings running back Adrian Peterson made a remarkable return this season some eight months after tearing an ACL — and nearly broke the NFL’s single-season rushing record

Griffin was optimistic before he entered surgery, tweeting early Wednesday: “Thank you for your prayers and support. I love God, my family, my team, the fans, & I love this game. See you guys next season.”