Admit it. You had almost forgotten about Tarvaris Jackson. The two interceptions in the penultimate game of last season, a 30-21 loss to Washington that pretty much eliminated the Vikings from the NFC playoff race. The subpar start that got him benched only two games into this season. Even the offseason hype that might have led one to believe the Vikings had found their quarterback of the future.

All of it a distant memory ... until 15 days ago. That's when Jackson stepped in for the injured Gus Frerotte late in the first half at Detroit, rallied the Vikings to a 20-16 victory and threw a curveball into how the team might approach its quarterback situation.

Any previous talk of Jackson had centered on whether he had a future with this franchise. It was Frerotte who led the Vikings to the top of the NFC North, and beyond 2008 all indications seemed to point to an offseason quarterback search.

But in the six quarters since replacing Frerotte, Jackson has thrown five touchdowns and no interceptions, and is responsible for two victories. Jackson's play will keep a now-healthy Frerotte on the bench today, and coach Brad Childress will continue to ride Jackson as long as he performs at a high level.

How long will it last?

The Vikings brain trust isn't going to go into any detail about the future as long as the team is in the playoff hunt, but internally they are going to have to decide if Jackson really has turned a corner.

"We talked about that a couple of weeks ago," Childress said. "We really don't go that far ahead until we get to the end of the year and kind of make an overall analysis of things. I'm just kind of week-to-week, day-to-day here."

In the excitement of how things are going, it might be easy to lose sight of the big picture. But the Jackson decision is going to be crucial if this franchise wants to achieve the type of lasting success that owner Zygi Wilf often talks about.

The Vikings could return to Mankato next summer with the quarterback trio of Jackson, Frerotte and John David Booty, and Frerotte could again emerge as the starter. Frerotte, though, will be 38 next July and is a year-to-year type of guy.

Wilf has shown a willingness to invest heavily in this product, and there is little doubt he would go for making a significant addition at quarterback, if that's what Childress and VP of player personnel Rick Spielman advise him to do.

The market won't be flooded with top-flight quarterbacks in free agency. Kerry Collins, Jeff Garcia and Kurt Warner are in the golden years of their careers, and names like J.P. Losman, Dan Orlovsky and Chris Simms don't create much excitement. The one significant free agent will be New England's Matt Cassel.

The most likely scenario, until Jackson's re-emergence, was that the Vikings would explore what it would take to pry Donovan McNabb away from the Eagles. McNabb is under contract through 2010, but after being benched in a November loss it appeared his run in Philadelphia might be near an end.

Childress was McNabb's position coach and then coordinator for seven seasons with the Eagles. But just as important, or perhaps more so, is that McNabb is extremely close with Vikings quarterbacks coach Kevin Rogers. Rogers was the offensive coordinator at Syracuse when McNabb was playing at the school, and McNabb endorsed Rogers for the Orange's then-vacant head coaching job this month.

Assuming McNabb can be obtained, his addition would not only create a buzz that would exceed that of the trade-and-sign for Pro Bowl defensive end Jared Allen last spring, but it also would end the game of hot potato the Vikings have been playing at the quarterback position since Childress came on board in 2006.

Jackson, though, is trying to make the case that the answer at the quarterback position already is on the roster.

Judd Zulgad • jzulgad@startribune.com