Favre has informed the Vikings he will not return to Minnesota for a second season, according to multiple reports.
Favre has sent text messages to teammates saying, "This is it," league sources told ESPN NFL Insider Adam Schefter.
Vikings tight end Visanthe Shiancoe said Favre texted his teammates and told them he plans to retire. Shiancoe added he did not receive any direct messages from Favre, but learned of the texts from several teammates.
"He told a couple guys on our team he's going to retire," Shiancoe said after practice on Tuesday. "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."
However, the Vikings reportedly are ready to increase Favre's salary for this season in order to get him to hold off on retirement for another year.
Sources told the Star Tribune that the Vikings have offered to increase Favre's salary to $16 million guaranteed -- $3 million more than he was scheduled to make this season, plus another $4 million in incentives that could potentially pay Favre $20 million total for the 2010 season.
Neither Favre nor the Vikings has confirmed the news.
Vikings coach Brad Childress said Tuesday that he has talked to Favre in the past 24 hours, but was unaware of the reports of Favre's apparent decision to retire.
"I'm not a big hearsay person," Childress said. "I've got to hear it from the horse's mouth."
Childress told the NFL Network that the Vikings would be prepared if Favre didn't return.
"The same plays are being installed whether [Favre] was here or the guys that are here are here," Childress said.
After the Vikings completed a morning practice, Childress would not confirm Favre's status with the team and called it a "fluid situation." He told reporters that he had not heard from Favre directly about the decision, but said he could have a message waiting for him from the quarterback.
With Favre, of course, nothing is ever necessarily final after 19 NFL seasons. He told the Vikings last year he wouldn't play, but changed his mind and joined them immediately after they broke training camp, with Childress even driving to the airport to pick him up. Camp this year ends on Aug. 12.
Owner Zygi Wilf, vice president of player personnel Rick Spielman and vice president of football operations Rob Brzezinski spent nearly the entire two-hour morning practice in a huddle. All three were unavailable for comment afterward.
"It wouldn't surprise me one way or the other whether he elects to play or whether he elects to retire," Childress said. "I think all of us can live with it either way. The big thing is that he's at peace with it."
Favre and his agent, Bus Cook, did not return messages from The Associated Press.
A family source told the Biloxi Sun Herald on Tuesday that Favre "has not made a commitment to play or a decision to return at this point."
Every Minnesota player asked about Favre after practice reacted with hesitation after three years of answering questions about Favre's future.
"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."
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."
Favre has waffled on 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 Game loss to the New Orleans Saints and had arthroscopic surgery in May.
"It's always back and forth with Brett," quarterback Tarvaris Jackson said. "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."
If Favre doesn't return, the Vikings' starting quarterback job likely will be decided in a training camp battle between Jackson and Sage Rosenfels.
The 27-year-old Jackson, drafted in the second round of the 2006 draft, has a 77.9 quarterback rating and has 21 touchdowns and 18 interceptions, passing for 3,643 yards in 33 career games.
The 32-year-old Rosenfels, acquired by the Vikings last year in a trade with the Houston Texans, has a career rating of 81.2. In 32 games, he has 30 touchdowns and 29 interceptions and has passed for 4,156 yards.
The Vikings also drafted quarterback Joe Webb in the sixth round of the 2010 NFL draft.
"I won't believe it until I see Tarvaris Jackson starting against us," Briggs said.
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."
Nearly everyone had assumed 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.
Childress shrugged off all the questions and admitted he didn't know whether Favre would really come back. The Vikings didn't pursue a trade for Donovan McNabb and declined to select a quarterback of the future in the draft.
Still, Favre took a beating in the loss to the Saints and said afterward that he would not take long to make a decision on returning for the second year of his contract. As the months ticked by, Favre posted a statement on his website reminding everyone that his ankle problems didn't mean his career was over.
If Favre decides to actually retire for good, it will end one of the most storied careers in NFL history.
A three-time league MVP (1995-97), Favre won Super Bowl XXXI 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.
Many of Favre's sacks came on scrambles, and so did the picks as he fearlessly tried to force the ball -- underhanded, left-handed, whatever worked -- where few, if any, could put it. He brought a sense of danger to the game and Vikings fans responded in droves. He was a classic gunslinger and has never minded the label.
"I would hope 20, 30 years from now, I'm remembered for something else besides records," Favre told the AP in 2007, when the annual summer waffling was still sort of new. "Whether I have them or don't have them. If that's the only way I'm remembered, apparently I didn't do something right or leave a good enough impression on the fans. ...
"I know when I leave the game, I'm going to miss it. 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.
"I feel like I've given every ounce of energy I can give every single time I stepped on the field."
Information from The Associated Press was used in this report.