MINNEAPOLIS (AP) — For the third straight offseason, Adrian Peterson will be recovering from surgery.

The Minnesota Vikings said their star running back had an operation Thursday to repair his adductor muscle, which is part of the groin. The team said Peterson was expected to be fully recovered in about six weeks, giving him plenty of time to heal before offseason workouts get going.

The procedure was performed by Dr. William Meyers at the Vincera Institute in Philadelphia.

Peterson rushed for 1,266 yards in 14 games, missing two in December due to a sprained right foot. The groin problem was lingering long before that, though, sapping him of some of his explosiveness. He acknowledged after a loss at Seattle Nov. 17 that the injury was bothering him “a lot.” Peterson gained only 65 yards on 21 carries that afternoon, albeit against the league’s best defense.

He still managed, two weeks later, to rush for 211 yards against Chicago, the fourth-highest total of his career. But then came the sprained foot in the snow Dec. 8 at Baltimore, and he played only once more, and not at full speed. He tallied 45 yards on 11 attempts at Cincinnati on Dec. 22 and said afterward he felt uncomfortable, a rare admission for one of the sport’s most confident and determined players.

Keeping him off the field is always hard.

“That’s just not my mentality, leaving these guys out to dry, just because, what the heck, my passion for the game,” Peterson said last month. “I love the game too much to sit out just because. If I’m out, you’re going to know that he can’t go.”

Peterson is 27th on the all-time rushing list, second only behind Steven Jackson among active players, and he has often stated his goal of someday passing Emmitt Smith for first place in history.