Vikings star Justin Jefferson left Sunday’s game against the Chiefs in the fourth quarter with a hamstring injury and did not return. After much confusion as to the severity of the injury and how long he would be out, now we know — Minnesota plans to place the star WR on injured reserve, according to NFL Media.

The exact timeline is TBD based on how long it takes Jefferson to heal and how he responds to treatment. But he is out at least four games in a crushing blow to the Vikings.

Jefferson slipped on the U.S. Bank Stadium turf while running a route against Chiefs cornerback Trent McDuffie late in Kansas City’s Week 5 27-20 victory. He was ruled questionable to return and did remain on the sidelines after limping off for medical attention. But he didn’t take another snap before the final buzzer, leaving rookie Jordan Addison to serve as Kirk Cousins’ top pass target.

Head coach Kevin O’Connell made a personal visit to Jefferson’s locker on his way to the podium after the game, attempting to console the wideout, who did not speak with reporters. On Monday, O’Connell told reporters that Jefferson would solicit multiple medical opinions on his hamstring.

“We’ve got to get the MRI of it and take a look and find out exactly what it is, where it is, if there’s any other factors that go into it and determine what the best decision (is) for him to get him back to 100 percent as fast as possible,” he said. “He’s down today. He obviously is one of the most ultra-competitors I’ve ever met, and shoot, he was trying to go back in the game as it was yesterday. So we’re gonna have to medically make a good decision and help kind of almost protect him from himself a little bit.”