The Kansas City Chiefs placed wide receiver Rashee Rice on injured reserve Thursday, sidelining him for at least the next four games.

Rice sustained a knee injury Sunday when quarterback Patrick Mahomes collided with his knee as Rice, Mahomes and other players were chasing a Los Angeles Chargers fumble that followed an interception.

Chiefs coach Andy Reid had already ruled Rice out for Monday night’s game against the New Orleans Saints.

Kansas City won’t know more about the extent of the injury until next week, Reid said Thursday, adding that Rice was waiting on the swelling to be reduced in his injured knee before undergoing further testing.

“We’re really hoping that things work out for the best, but let’s just see where it goes and leave it up to the doctors to see,” Reid said.

“Rashee’s had a phenomenal year. Unfortunately, in this league injuries happen, and life goes on, so we always expected the next guys to step up and roll, and it’s no different now. There’s not another Rashee. There [are] other guys, though, that are very, very good, so we’ll be fine.”

Rice leads the Chiefs with 24 receptions and 288 yards receiving in four games this season. He’s also tied for the team lead with two touchdown receptions.

ESPN’s Adam Teicher contributed to this report.