The NCAA Football Rules Committee recommended on Wednesday a change for the 2014 season that will allow defensive units to substitute within the first 10 seconds of the 40-second play clock.

The exception would be the final two minutes of each half.

"This rules change is being made to enhance student-athlete safety by guaranteeing a small window for both teams to substitute," said Troy Calhoun, head coach at the Air Force Academy and chair of the committee, which met in Indianapolis.

"As the average number of plays per game has increased, this issue has been discussed with greater frequency by the committee in recent years and we felt like it was time to act in the interests of protecting our student-athletes."

Under this rule proposal, a hurry-up offense will not be allowed to snap the ball until the play clock reaches 29 seconds or less. If the offense snaps the ball before the play clock reaches 29 seconds, a 5-yard, delay-of-game penalty will be assessed.

Under current rules, defensive players are not guaranteed an opportunity to substitute unless the offense substitutes first. This part of the rule will remain in place in scenarios where the play clock starts at 25 seconds.

The rules committee also proposed an alteration involving the instant-replay review on targeting fouls, which includes the ejection of the player committing the foul along with a 15-yard penalty.

The committee recommends that if the instant replay official rules that a disqualification should not have occurred, and if the targeting foul is not accompanied by another personal foul, the 15-yard penalty for targeting should not be enforced.

All rules proposals must be approved by the NCAA Playing Rules Oversight Panel, which will discuss the football rules changes March 6.