Boyd was injured in the first quarter following an incomplete pass. He leaped to attempt to grab a deep ball from Bengals quarterback Ryan Finley but was unable to traverse two Steelers defenders.
On his way down, Boyd slammed the back of his head against the field at Cincinnati's Paul Brown Stadium.
After a brief evaluation in the team's sideline injury tent, Boyd walked to the locker room without his helmet.
Boyd, who played high school ball less than 17 miles from Pittsburgh's Heinz Field and attended college at Pitt, finished with no catches.