The surgery comes three days after the NFL rookie known as RG3 reinjured his ailing knee at least twice in Sunday's playoff game against the Seattle Seahawks. The Redskins lost, 24-14.
The two-hour procedure was meant to repair Griffin's torn lateral cruciate ligament or LCL - a band of fibrous tissue that connects the thigh bone to the outer bone of the lower leg - as well as his anterior cruciate ligament or ACL, which he tore initially in 2009. The new ACL injury occurred in grafted tissue used to treat the 2009 tear, ESPN reported.
While Griffin will need several months of intense physical therapy to strengthen and stabilize his knee, he assured fans he'd be ready for next season.
"Thank you for your prayers and support," he tweeted today. "I love God, my family, my team, the fans, & I love this game. See you guys next season."
Griffin left two regular season games early and missed a third entirely because of his knee, according to the Associated Press. But the No. 2 draft pick still managed to set the league record for best season passer rating by a rookie quarterback and lead the Redskins to their first NFC East title in 13 years.
Griffin had been wearing a knee brace since spraining his LCL in a December game against the Baltimore Ravens. He hurt his knee again in the first quarter of Sunday's game, but kept playing. He had to leave the game in the fourth quarter after trying to recover a bad snap, raising questions about whether Redskins coach Mike Shanahan and the team's medical staff should have pulled him out sooner.
While ACL injuries have ended football careers, Griffin wouldn't be the first NFL player to go from tear to triumph. Minnesota Vikings running back Adrian Peterson tore his ACL and medial collateral ligament Christmas Eve 2011, and returned in 2012 to come within nine yards of the league's single-season rushing record. He ran for more than 2,000 yards and is on most lists of league MVP favorites.