No coach had more faith in his quarterback than coach Brad Childress had in Tarvaris Jackson, who has made 16 career starts. But Childress named Frerotte the starter for the remainder of the season, announcing the decision at his Wednesday media availability.
"I'm just not seeing right now the aggressiveness from Tarvaris that I saw throughout the offseason, training camp, the two preseason games that he played in," Childress said. "And part of it may be experience. I know Gus will give us that. And I know his approach will also lend itself to that."
Jackson was 8-4 as a starter last season, even though he completed only 58.2 percent of his passes and had a 70.8 quarterback rating.
This season started even slower for Jackson. He completed only 30 of 59 passes for 308 yards in two games, in an offense that is ranked 24th in the league in passing despite a strong running game from Adrian Peterson.
"I wish I had more time, but it's Coach's decision," Jackson said. "I don't want all my work to go to waste. I felt like I've come this far and I've worked so hard to get to where I am now and I'm going to continue to work hard and keep trying to get better and take it one day at a time. Whatever happens, happens."
Jackson has been playing with a sprained medial collateral ligament in his knee, an injury that forced him at times to wear a brace. In the season opener, a 24-19 loss to Green Bay,
he threw a game-ending interception that sealed the Packers' victory.
Vikings fans booed him throughout Sunday's 18-15 loss to the Indianapolis Colts when the Vikings, despite a 160-yard rushing day by Peterson, had to settle for five field goals.
"I know there's many other plays, there's a lot of other people that have to step up," Childress said. "But then when you go back through and look at the tape, and most importantly be able to sit across from the young man and want to be able to verify what you're feeling -- it's kind of like looking in your kids' eyes and saying one [thing] and feeling another."
It's an abrupt and drastic move for a team that entered the season with sky-high expectations after spending $60 million in guaranteed money to position itself as an NFC contender.
Only two weeks in, the Vikings already are two games behind NFC North-leading Green Bay with games against Carolina, at Tennessee and at New Orleans coming up.
"We're 0-2 right now, and the key thing, probably one of the reasons Coach made the decision, was maybe because we need to get something to get us over the hump to get us a win," Frerotte said.
With a tough home game coming up against the Carolina Panthers, Childress decided to go with the strong-armed Frerotte. Frerotte, 37, is in his 15th season, and spent the past two seasons as a backup in St. Louis.
"I was very surprised," receiver Bobby Wade said. "I didn't anticipate that. Obviously it's the coach's decision and the administration's decision and we have to run with that."
Frerotte was signed in the offseason to be Jackson's backup, but now finds himself trying to turn around a team that had high expectations.
"I can't say that it was a shock, because I've been playing for a long time," Frerotte said. "I've been through a lot of shocking moments in my time, so nothing really shocks me anymore. It's obviously something Coach wanted to do."
Frerotte has been with seven teams, but this is his second tour with the Vikings, having spent 2003 and 2004 in Minnesota.
Frerotte has completed 54.2 percent of his passes during his career for 19,134 yards and a 74.3 quarterback rating. He's 37-44-1 as a starter.
"I've never been part of a team where a quarterback was benched that early on," said Carolina quarterback Jake Delhomme, whose Panthers play at the Metrodome on Sunday. "But it can be a spark to a team."
Frerotte showed in training camp this year that his arm still has plenty of juice in it. Wade said the playbook may open up with a veteran in there, as opposed to a player who has had only 16 total starts.
"I think the coach was keeping it limited for a reason, obviously not to try to put too much on a young player and trying to get a guy more comfortable and more confident," Wade said. "You might see some things change this week with Gus back there."
Childress said that barring injury, Frerotte will be the quarterback for the rest of the season. However, Childress added he hasn't given up on the 25-year-old Jackson as an option for the team's long term.
"While I know he doesn't like it, I'd worry about him if he did like it," Childress said. "I know he'll make the most of it."
Said Jackson: "I could easily hold my head low, keep my head down, you know, be a cancer to the team. I'm still frustrated and mad about the situation, but I'm going to use that as motivation to try to get better and just better myself for the future."
John Clayton is a senior NFL writer for ESPN.com. Information from The Associated Press was used in this report.