The chairman of the NCAA Football Rules Committee says a proposal to prohibit snapping the ball until at least 10 seconds run off the 40-second play clock should not go forward if there's no hard evidence showing up-tempo offenses endanger the safety of defensive players.

Air Force coach Troy Calhoun is the chairman. He said Tuesday he has yet to see a medical study linking the rapid pace of an offense to potential health issues for defensive players.

The comment period for the proposal ends March 3. The Playing Rules Oversight Commission, which meets March 6, would have to approve the proposal.

This is a non-rules change year for the NCAA, but exceptions can be made for rules that affect player safety.