EDEN PRAIRIE, Minn. — Once again, Brett Favre says he isn't sure what he wants to do.

The 40-year-old quarterback told ESPN that he needs surgery on his left ankle in order to play this season for the Minnesota Vikings. In an e-mail posted to ESPN.com on Friday, Favre said he's deciding whether to have the procedure or finally retire after 19 seasons.

Currently holding all the NFL's major career passing records, Favre will turn 41 in October. He told ESPN the injury that hobbled him three months ago in the NFC championship game still causes swelling and pain, and said orthopedic surgeon Dr. James Andrews told him an operation is unavoidable if he wants to keep playing.

"This decision would be easy if not for my teammates and the fans and the entire Vikings staff," Favre said in the e-mail. "One year truly felt like 10 — much like Green Bay for many years. That's what I was missing in my heart I suppose, a sense of belonging."

According to ESPN, Favre didn't specify the diagnosis or elaborate on a timetable for recovery from such a surgery.

Favre's agent Bus Cook didn't immediately return messages left by The Associated Press. Vikings officials, including coach Brad Childress, were not available before a Friday afternoon rookie minicamp.

Favre was a mainstay with the Green Bay Packers before waffling on his playing status and departing in an ugly divorce that got him traded to the New York Jets. After a so-so season in New York, he announced his retirement in early 2009 for the second time, then reconsidered and signed with the Vikings.

Favre beat the Packers twice, and he was heartily booed in his appearance at Lambeau Field. With or without Favre, Green Bay should give the two-time defending NFC North champion Minnesota stiff competition for the division title next season.

"Somebody tell Brett to have that surgery so I can make up for last year!!!" Packers linebacker Nick Barnett posted on Twitter.

He enjoyed one of the best seasons of his storied career, throwing for 33 touchdowns and only seven interceptions and guiding the Vikings to a 12-4 record. They finished just short of the Super Bowl, falling in overtime to New Orleans after an ill-advised pass by Favre was picked off by the Saints to stop a promising fourth-quarter drive.

Now Favre and the Vikings are back in the same place as last year.

The quandary then was whether he wanted to have surgery to repair a partially torn biceps tendon in his right shoulder, a decision he made and didn't regret. That surgery was with Andrews, the noted physician who works in Alabama and Florida.

Favre worked out last summer at the local high school in his Mississippi hometown, and video clips of him firing passes in a cap and a cutoff T-shirt to teenage wide receivers became must-see TV as intrigue about his intention increased.

His arm took a while to feel strong and it still took some persuasion from Childress, but three weeks into training camp Favre arrived and quickly ingratiated himself into the locker room and the fan base.

Favre is under contract for $13 million this season, but that's only if he plays. The Vikings hope he does, with unproven options in Tarvaris Jackson and Sage Rosenfels on the roster behind him. They declined to take a quarterback in the NFL draft last weekend.

Childress and the players have repeatedly said they're fine with Favre taking his time to recuperate, refocus and recommit to playing, even if that means again skipping the grind of training camp.