Vikings General Manager Rick Spielman has maintained his belief in quarterback Christian Ponder in part because of statistical analysis that suggests Super Bowl MVPs Drew Brees and Eli Manning were at similar stages in their second seasons.

That's fine. After all, it's still too early to definitively say Ponder's career won't take off in that manner.

But for anyone to suggest Ponder's career arc can only go up is to conveniently ignore all the Jason Campbells, Kyle Bollers, Rex Grossmans and, yes, Tarvaris Jacksons who have stood where Ponder stands heading into his 23rd NFL start.

Ponder is 8-14 with a 59.1 career completion percentage heading into Sunday's game against the Bears at Mall of America Field. Jackson was 10-12 with a 57.7 completion percentage heading into his 23rd start. He also was already gone from Minnesota, finally tossed aside after 20 starts over five seasons.

Ponder has thrown 27 touchdown passes and 24 interceptions. Grossman was at 27 and 22 en route to the Super Bowl in 2006.

Coach Leslie Frazier's steadfast defense of Ponder is starting to sound a lot like Bears coach Lovie Smith repeating the words "Rex Grossman is our starting quarterback" ad nauseam in that slow, Texas drawl through the 2006 and 2007 seasons.

"As a coach, if you believe in your guy and what you're doing, it's easy to do," Smith said. "I wouldn't necessarily say you have to defend him, but you have to do that a little bit. If you feel like it gives you the best chance to win and you feel good about that, nothing else really matters."

But after Grossman's 23rd start, he started only eight more games before the Bears finally gave up on the 22nd pick of the 2003 draft.

The Vikings are saying all the right things about believing in Ponder. But the truth is no one knows how the story will end. Or how long it will take to unfold.

"At that position, it varies from guy to guy," Frazier said. "In regards to Christian, we're still in that process where we see some things where he's definitely still getting better from a season ago. We've seen it during the offseason, we've seen it during the season. There are still some areas where we know he has to improve, where he knows he has to improve.

"The clock is still ticking on his improvement and development. We are not at a point where we want to throw in the towel on Christian Ponder. He's going to get better and he's going to play better this Sunday. I really believe that."

Sunday's game essentially is a playoff contest since it's so unlikely that the Vikings (6-6) could make the playoffs at 9-7. So Ponder's 23rd NFL start will be the most important of his career. It also could be the last one of any significance this season since a loss would basically render the final three games as meaningless no-pressure garbage time.

At this point, Ponder is in that danger zone for a young franchise quarterback and the team that drafts him: He's not good enough to trust but not bad enough to give up on.

So today's game is a huge step for Ponder. And much like his eventual career arc, that step could go either way.