LULING, Texas -- Autopsy results on a 15-year-old football player at Luling High School who died after returning home from a morning workout weren't expected to be available until next week, Travis County Justice of the Peace Garland Grice said.

An autopsy was ordered in Friday's death of Steven Taylor, but officials said they don't believe it was heat-related. Preliminary inquiries indicate Taylor may have gone into cardiac arrest.

The team's morning practice consisted of noncontact walk-throughs in shorts and pads. Temperatures were in the 80s.

"If I find out that something that occurred at practice caused this, I would be really surprised," said David Creed, the city's deputy police chief.

Taylor had no history of any medical conditions, said James Matthews, Luling High School's principal.

"It's a tremendous shock," Matthews said. "His friends and family don't know what to think; there's no explanation."

A report from an early August physical examination of Taylor was on file at the school, Matthews said.

Taylor was unconscious and not breathing when authorities went to his home Friday morning after receiving a 911 call from his mother. He was taken to Seton Edgar B. Davis Hospital, where he was pronounced dead.

Creed said he was told Taylor did not behave unusually at practice or after arriving home, where he told his mother he was tired. After hearing a noise from his room, she found him on the floor.

Luling is 50 miles northeast of San Antonio.

Head football coach Jeff Rochat said Taylor underwent a physical examination two weeks ago and was cleared to play.

"If you're going to be in this profession, you want 100 Steven Taylors to coach," Rochat said. "He was a great athlete, a great student and a school favorite. I've been going through shock for most of the day. It's a tragedy, and we don't have any answers right now."