John Sullivan not yet certain when he will return for Vikings

Vikings center John Sullivan, center, had back surgery last month and has yet to resume lifting weights. AP Photo/Charles Rex Arbogast

EDEN PRAIRIE, Minn. -- Minnesota Vikings center John Sullivan is ineligible to play until at least Week 9 because of a herniated disc in his back that required surgery earlier this month. Sullivan, however, said he's "not certain" whether he will be recovered sufficiently to play by that point.

Speaking to reporters for the first time since he began having back spasms last month, Sullivan said he is about two weeks away from starting a weightlifting regimen.

"It's pretty early in the process now to speak on [a return date]," he said. "I'm eligible to come off [short-term injured reserve] and play Week 9. That's my hope, to do that."

Sullivan's replacement has been veteran Joe Berger, one of two reserve linemen who have been pressed into starting duty. Rookie T.J. Clemmings is playing right tackle in place of Phil Loadholt, who tore an Achilles tendon during the preseason.

"Obviously that's not ideal to lose your two most experienced guys like that," Sullivan said. "But I think it just comes with the territory. Especially at center. You feel responsible for the guys around you. And the only thing I can do to do right by them is to follow the course of the plan for treatment for rehab and get back out there as soon as I can."