Boyd (knee) was diagnosed with a sprained MCL and is expected to miss a few weeks, Ian Rapoport of NFL Network reports.
With the Bengals heading into a Week 6 bye, Boyd may have a shot to avoid missing any games. He was forced out of Sunday's 20-16 win over Buffalo, leaving extra snaps for Alex Erickson and Cody Core. Rookie first-round pick John Ross (knee) figures to push for the No. 3 receiver role if he can ever stay healthy for more than a week or two.