Calais Campbell injured his knee during the Arizona Cardinals' loss to the Denver Broncos in what was a dirty play.
Julius Thomas was called for an illegal chop block on the play, a 15-yard penalty which negated a touchdown. Ryan Clady worked in tandem with Thomas on the play.
Bruce Arians said Campbell has a sprained MCL and will miss two to four weeks.
"That was the dirtiest play I've seen in 37 years," Bruce Arians said, calling it a "premeditated high-low."