Frazier said the decision was based solely on what gives the team the best chance to win.
"I know I have a lot of football left in me," McNabb said.
"He is the head coach and decisions are made," McNabb said. "At this particular point, it's for me to continue to prepare and make sure that we continue to support Christian and make sure that he's ready. But most important for me, is to prepare because I'm just one play from going back in. Just make sure I'm ready when called upon and try to lead us to victory."
McNabb will remain on the team as the backup, and Frazier says he handled the demotion professionally and pledged to help Ponder succeed.
"It does not mean that I am giving up on the 2011 season," Frazier said. "The decision was made purely based on what would give us the best chance to win on Sunday. That's why the decision was made. I didn't feel or sense that staying status quo was going to get us a win on Sunday."
With the Vikings 1-5 and coming off of a 39-10 loss at Chicago, the move hardly came as a surprise. McNabb has struggled mightily for most of the season in this new offense and has never looked in rhythm while throwing from the pocket.
The Vikings passing offense ranks 31st in the league and McNabb ranks 29th in the league in touchdowns, 26th in yards passing and 19th in completion percentage. Frazier declined to give him a vote of confidence after a 39-10 loss in Chicago on Sunday night.
It's the second straight season that McNabb has been benched because of his performance, but his close relationship with Frazier seems to have made this one smoother than how things went down last year in Washington under head coach Mike Shanahan and offensive coordinator Kyle Shanahan. McNabb's agent, Fletcher Smith, openly challenged how the two coaches handled the situation, calling it disrespectful and "unprecedented for a six-time Pro Bowl quarterback such as Donovan."
Ponder completed 9 of 17 passes for 99 yards in the fourth quarter against the Bears on Sunday night, his first NFL game action in the regular season. He also rushed for 8 yards and a first down to keep his first drive going, showcasing some of the athleticism that was apparent during his time under center in the preseason.
"When he got a chance to play in the game on Sunday, some of the things he did let me know that the game is not too big for him," Frazier said. "It's not too fast for him. He did some good things in a short period of time."
Newton's quick command of the offense and playmaking ability has been one of the most pleasant surprises of the season, Dalton has been a steady contributor and key to the Bengals' fast start while Gabbert has struggled in the early going with the Jaguars.
Now Ponder will get the chance to show how he measures up to the rest of a promising rookie class.
The Vikings selected him 12th overall in April, saying at the time that the Florida State star was the most NFL-ready quarterback in the draft. All signs were pointing to Ponder taking over from the very beginning, but the summer-long lockout prevented him from getting the practice time needed to learn the offense and get on the same page with his new teammates.
So Frazier turned to McNabb, a player he got to know very well as an assistant with Philadelphia. The trust the two had in each other was one of the biggest factors in completing a trade with Washington to bring the 13-year veteran to Minnesota, with Frazier saying at the time that he thought McNabb was the best option available to help the Vikings contend in 2011.
"I can't say that on July 31 I thought we'd be at 1-5," Frazier said, thinking back to the day the Vikings acquired McNabb. "There's no way I could've predicted that. I thought we'd be further along than we are. I have a ton of respect for Donovan both personally and professionally as well. But the decision was based on what's going to be best for our team and what's going to give us the best chance to win."
Frazier said he didn't regret his decision to bring McNabb in and was careful to point out that everyone -- not just the quarterback -- is to blame for the team's struggles. The offensive line has played poorly, offensive coordinator Bill Musgrave hasn't found a play-calling rhythm yet and the receivers lack a downfield threat to stretch the defense.
"This move is not just about the quarterback position," Frazier said. "Our entire team has to play better in order for us to win on Sunday."
Teammates took the news in stride, throwing their support behind the rookie and hoping the change will give them the jolt they need.
"You get to this point in the season and you're kind of looking for a spark or something to get you going, and obviously coach Frazier and the coaching staff felt like this was something that needed to be done to get us going," left tackle Charlie Johnson said. "So we're behind it, we're on board."
The Packers (6-0) are the league's only undefeated team and have been looking every bit the part of the Super Bowl winner they were a year ago.
They'll be coming after Ponder and could be going through a makeshift offensive line. Right tackle Phil Loadholt (knee) and center John Sullivan (concussion) did not practice on Wednesday and left guard Steve Hutchinson (knee) and Johnson (triceps) are expected to play through minor injuries.
It will be up to Ponder to make the transition from rookie backup to the one everyone in the huddle will be looking to.
"I don't think it's hard to do," Ponder said. "I think at the quarterback position, that leadership position comes natural. I don't really think anything of it. I'm just going to go out there and be the same person I've been for the last five years since college. I don't think it's going to be a tough transition."
Information from The Associated Press contributed to this report.