The Vikings got some good news on backup running back/returner Lorenzo Booker, who left Saturday night's game because of a back injury.

An MRI revealed a disk that's out of place but, with treatment this week, Booker is expected to be ready for the regular-season opener at San Diego on Sept. 11.

Booker left the game after running a route and collapsing without contact. He won't play in Thursday's preseason finale against Houston.Â