MANKATO, Minn. - Even though Brett Favre has told some of his teammates he's calling it a career, the Minnesota Vikings are hoping for one last change of heart from the quarterback who just can't stay retired.

Favre has started to contact teammates and Vikings officials to say he will not return for a 20th NFL season, tight end Visanthe Shiancoe said on Tuesday evening.

"He told a couple guys on our team he's going to retire," Shiancoe said after practice. "He hasn't told me yet. I'm going to check my phone right now, but it hasn't been said publicly yet so I don't know what to believe."

Earlier Tuesday, a person with knowledge of the situation told The Associated Press that the 40-year-old Favre contacted the Vikings to say he wouldn't return this season because his injured left ankle is not responding as well to surgery and rehabilitation as he had hoped. The person spoke on condition of anonymity because no official announcements were made.

Coach Brad Childress said Favre had not told him directly that he plans to retire as of Tuesday morning. The coach would not confirm Favre's status with the team, calling it a "fluid situation," and he was unavailable for comment after the evening practice. Owner Zygi Wilf declined to comment.

"I'm not a big hearsay person," Childress said. "I gotta hear it from the horse's mouth."

As always with the former MVP, things could change. Favre and his agent, Bus Cook, did not return messages from the AP.

"I plead the fifth on everything," defensive end Jared Allen said. "I love Brett and he reserves the right to do what he wants to do. We obviously love him as a teammate. We'd like to have him back. But until it's official, I'll believe it when I see it."

Fair enough. With Favre, nothing ever seems final. He told the Vikings last year he wouldn't play, but changed his mind and joined them immediately after they broke training camp. Childress even drove to the airport to pick him up for his 19th NFL season. Camp this year ends on Aug. 12.

Favre can expect some calls from teammates urging him to reconsider.

"I'm going to try to get him here every chance I get," Shiancoe said. "I'm going to try to send him texts or something. But at the same time, I know he made a decision for a reason and hopefully that reason transforms or gets better."

Star running back Adrian Peterson said he still hopes that Favre will be handing him the ball in the season opener on Sept. 9 in New Orleans. Peterson said he exchanged text messages with Favre on Tuesday but declined to give details.

"I'm still up in the air like you guys trying to figure out what's going to happen," Peterson said. "I'm sure he'll make the best decision for him."

This uncertainty is nothing new for the Vikings, who have spent the last three years answering questions about Favre's future.

"It's always back and forth with Brett," said quarterback Tarvaris Jackson, in line to get the starting job if Favre is gone. "It's his decision. He deserves the opportunity to decide when he's going to retire or not, whether he wants to retire or not. It's up to him. Right now, I'm just trying to focus on getting better."

Favre has considered retiring every summer since 2002. It led to an ugly parting with the Packers that got him traded from Green Bay to the Jets in 2008. 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.

He had one of his best seasons last year, with career bests in completion percentage (68.4), quarterback rating (107.2) and fewest interceptions (7), while throwing for 33 TDs and 4,202 yards to lead the Vikings to an NFC North title. He hurt his left ankle in the NFC championship loss to the New Orleans Saints and had arthroscopic surgery in May.

Favre was under contract for $13 million this season, but only if he plays.

Nearly everyone has been assuming Favre would return and he did nothing to discourage that. He threw passes for a second straight summer with high school students in Hattiesburg, Miss., joked about playing until he's 50 and said playing another year wouldn't worsen his already-damaged ankle.

Packers linebacker Nick Barnett said he didn't know whether to believe the latest news.

"It's like believing in Santa Claus. You get gifts, but you ain't seen Santa Claus," he said. "We'll see what happens ... If he does retire, congratulations. It's a well-deserved retirement. But if he does come back, we'll be gunning for him the same way."

If Favre decides to actually retire it will end one of the most storied careers in NFL history. A three-time league MVP (1995-97), Favre won the Super Bowl in 1997 with the Packers. His 11 Pro Bowl appearances are the most ever by a quarterback.

Indeed, Favre holds most major NFL records for a quarterback, including career touchdowns (497), yards passing (69,329); wins (181); and seasons with at least 3,000 yards passing (18).

Of course, he also has thrown the most interceptions (317) and been sacked 503 times - a long, long history of wear and tear.

"To be real with you it's going to be a big setback," Shiancoe said of the prospect of losing Favre. "We are all feeling it today. We are feeling it today to be real. But at the same time we all understand ... he just has to do what he has to do."

Retirement would also mean that the last pass of his career was an interception. Tracy Porter picked off a forced throw from Favre with the Vikings in New Orleans territory at the end of regulation, preventing an attempt at a game-winning field goal. Favre watched helplessly from the sidelines as Drew Brees drove the Saints for the winning field goal in overtime.

"I know when I leave the game, I'm going to miss it," Favre told The Associated Press in 2007, when the annual summer rite of indecision was still novel. "I know that. I'm not going to sit here and say, when I leave, it's over and I felt like I've done everything there is to do."

Cowboys quarterback Tony Romo, who grew up in Wisconsin as a Favre fan, said he was surprised the veteran might hang it up after playing so well last season.

"If it is (true), then we were lucky enough to watch an unbelievable talent and great guy," Romo said. "But it's better to go the year before than a year too late."