Vikings QB Jackson out 4-6 weeks after surgery

The Minnesota Vikings will consider adding a backup quarterback this week, after rookie Tarvaris Jackson underwent arthroscopic surgery Monday to repair meniscus cartilage damage to his right knee.

Coach Brad Childress said Monday that the surgery proceeded without complication and that Jackson, the last of the team's three selections in the second round of the 2006 draft, has already begun treatments. Vikings officials have not offered a timetable for Jackson's return to practice, but the former Alabama State star will likely be sidelined 4-6 weeks.

The injury occurred last week in practice and Childress announced then that Jackson would undergo surgery when the swelling subsided.

With Jackson sidelined, Minnesota has only two quarterbacks, starter Brad Johnson and backup Brooks Bollinger, on the roster. Childress indicated that Minnesota will audition quarterback candidates this week for the No. 3 job and probably sign someone to help take the practice load off Johnson and Bollinger.

"My understanding with his 'rehab' [for Jackson] is that it's not a forever kind of thing," Childress said. "We'll probably have somebody in here to work out in the next couple days. You really don't want the [two remaining] guys taking all those turns, when it's the practice team reps as well, so just to have another arm in there we'll probably go ahead and sign somebody."

Jackson did not play in any of the Vikings' first three games.

The 64th player chosen overall in this year's draft, Jackson was a mild surprise at that point in the lottery, with most scouts rating him more a third- or fourth-round prospect. But the Vikings' personnel department likes Jackson's abilities and feels that the former Division I-AA standout can compete for the starting job down the road.

Jackson threw for 2,941 yards and 29 touchdowns in his senior season. He transferred to Alabama State after beginning his college career at Arkansas.

Senior writer Len Pasquarelli covers the NFL for ESPN.com.