Favre, who will turn 40 on Saturday, has completed 48 of 77 passes for 572 yards with five touchdowns and one interception in victories over San Francisco and Green Bay. That includes a three-touchdown, 271-yard performance against his old team, the Packers, in a 30-23 victory on Monday night.
This comes after Favre threw only 48 passes and completed 37 of them for 265 yards with three touchdowns and no picks in the Vikings' victories at Cleveland and Detroit to open the season.
Favre's performance has helped the Vikings to a 4-0 start, an extremely encouraging stat for Minnesota considering 84 percent of the teams that have won their first four games have advanced to the postseason since the NFL began its current playoff format in 1990.
The Vikings would seem to have an excellent chance to improve to 5-0 on Sunday when they play at winless St. Louis. Certainly Peterson could be a significant factor in that game - the Rams are 24th against the run - but it's clear now that if Favre needs to carry much of the load he can do it.
One of the reasons is because Favre's throwing arm has healed after he underwent surgery in May to repair a torn biceps tendon. Favre has been throwing absolute darts for the past two weeks and doesn't appear to be having any of the same types of trouble he had late last season with the New York Jets.
"The arm feels great," Favre said. "It didn't feel that great last year. I'm not going to make any excuses. As the season progressed last year, I didn't make good decisions. I did not play as well as I would have liked, and my arm didn't feel very good. It feels a lot better, and I feel like it is showing."
It certainly did Monday night as Favre put on a prime-time performance that earned him NFC Offensive Player of the Week honors.
The question now becomes when do teams start focusing some of their efforts on Favre and perhaps allowing Peterson some room to breathe? That might never happen, but this clearly is getting into the territory of pick your poison when it comes to the Vikings offense.
Peterson hasn't had a 100-yard rushing game since Week 1, but he is still second in the NFL with 412 yards and already has five touchdowns.
In some ways this has to be what coach Brad Childress envisioned when he brought Favre to the Vikings. Minnesota finally has a quarterback that can make teams pay for focusing their efforts on Peterson.
So how much of an impact has Favre had on the Vikings' success?
"You can't quantify that," Childress said. "He'd be the first to tell you it's a team game. He's doing his role as the quarterback of this football team and what we're asking him to do. He's giving little pep talks. He's cracking people on the rear end. Doing a good job of communicating. All the things that a quarterback and leader has to do.
"With that said, he came to this team because it's a good team, defensively, offensively and special teams. I wouldn't want to pile any more on it than what it is. Has he made some great throws? Yeah, he's made some great throws. And he's a good player. I don't mean to take that down. But for me to saddle up and say, we're 4-0 because of that guy, he wouldn't want that and I wouldn't want to say that."
SERIES HISTORY: 34th regular-season meeting. Vikings lead series, 17-14-2. The teams also have met seven times in the postseason with the Vikings holding a 5-2 advantage.
BY THE NUMBERS: 2 — Times before this season that Brett Favre-led teams have started 4-0. In 1998, the Packers finished 11-5 and lost a wild card game to San Francisco. In 2007, the Packers finished 13-3 and lost to the New York Giants in the NFC Championship Game.
QUOTE TO NOTE: "He's still got great command of the football. Whether the command is touch or velocity or being able to pump and let it go. He is what he is. He's a great competitor. He's steely-eyed when it comes to competing." — Vikings coach Brad Childress on quarterback Brett Favre.