Campbell, who was part of a three-way playoff at the Masters, was hurt playing a shot around the 17th green during Fridays second round at the Colonial Country Club. Afterward, he stood with several others from his group, then dropped down to the ground.
The U.S. Open at Bethpage Black starts June 18.
Campbell shot a 3-under 67 in the first round. Starting at No. 10, he was 2-under through seven holes when he was hurt.