Oakland’s Skyline High is ending its varsity football season early because it no longer has enough players available, the school says. Its principal cited injuries, transfers and other circumstances affecting the roster.

Skyline is the second East Bay school in a week to cancel a varsity season. Mount Diablo High called off its season amid player safety concerns, leaving Benicia High to find another opponent for its homecoming game.

It is unclear whether concerns about head injuries are driving students away from football. Dr. John Yue, a UCSF neurological surgery assistant professor, said awareness of head injuries has grown and more parents seek care when their children are hurt.

Skyline, whose football program was once led by the late John Beam, says it will recruit student athletes through the rest of the school year with the goal of rebuilding for next season.