Viking quarterback Christian Ponder and running back Adrian Peterson both practice on a limited basis Friday and both are listed as questionable for Sunday's game at Detroit. Ponder didn't practice on Wednesday or Thursday while Peterson was limited in practice on both Thursday and Friday after not practicing on Wednesday. If Ponder can't play then Joe Webb will get the start at quarterback. Webb has been taking the first team snaps. Toby Gerhart will get the majority of the carries if Peterson cannot play.