Ryan Sakamoto of Niner News reported via Twitter that rookie tight end Blake Bell had suffered the same injury, but that tweet was later deleted. The other player to suffer the injury was actually wide receiver Issac Blakeney.
Ellington has been impressing during training camp, but the injury should not keep him out for very long.
His injury is not related to the hamstring injury that kept him out of offseason workouts.
The 49ers are scheduled to practice today at 4:15 PM at the practice fields behind the team's headquarters which sits next door to Levi's Stadium.
#49ers WR Bruce Ellington has muscle strain and won't practice today, Jim Tomsula said.
— Eric Branch (@Eric_Branch) August 4, 2015