"In his third offensive system in as many years, Donovan McNabb has had a short window in which to pick up the Vikings' offense.

But even during his one-year Washington debacle, his regular-season debut wasn't anything close to this bad. In fact, in McNabb's first game with the Redskins last season, he completed 15 of 32 passes for 171 yards in a 13-7 win over Dallas.

So what happened to stall the Vikings' passing attack to the point of futility in Sunday's 24-17 loss at San Diego?

In easily the lowest passing total of his career as a starter for a full game, McNabb recorded two second-half yards on 1-of-6 passing to finish with 39 yards.

Wide receiver Michael Jenkins points to third down, where the Vikings attempted six conversion attempts of six yards or longer.

Despite Adrian Peterson's productivity, rushing for 98 yards on 16 carries, the Vikings didn't have the ball long enough - 9:04 and 17 plays in the second half - to find a balance between run and pass.

The Vikings ran Peterson on nine of their 15 first-down plays and started two of their four drives in the second half with consecutive Peterson runs."