Jerick McKinnon's season is officially over. The Vikings placed the promising rookie running back on injured reserve because of a lower back injury.

McKinnon had been dealing with the injury since the middle of November, when he hurt himself lifting weights at the team facility. McKinnon played a couple of games with the injury, but he sat out last week's win over the Panthers and was ruled out again for Sunday's game against the Jets.

According to a league source, McKinnon will get a procedure done on his lower back that will shut him down for about eight weeks. That would mean he could return by the start of spring workouts.

McKinnon played 11 games for the Vikings this season, including six starts, and leads the team with 538 rushing yards on 113 carries but no touchdowns. He added 27 catches for 135 receiving yards.

The Vikings drafted McKinnon, a former triple-option quarterback at Georgia Southern, in the third round of May's NFL draft, thinking that he would be a pass-catching change of pace from star back Adrian Peterson. But when Peterson was put in limbo after a child abuse charge, McKinnon took on a larger role, spelling veteran Matt Asiata at first before taking over as the starting back in Week 6.

With McKinnon now out for the season and with Peterson awaiting word on whether an arbitrator will overturn his season-ending suspension — a ruling on Peterson's appeal could come sometime next week — the Vikings plan to go with a committee approach with Asiata, Joe Banyard and Ben Tate.

The Vikings promoted defensive end Justin Trattou from the practice squad to fill the open spot on the 53-man roster. And they bought back safety Ahmad Dixon to the practice squad to replace him.