The NCAA Football Rules Committee is still waiting for data supporting the 10-second substitution proposal.

Last week, a rule change was proposed to give defenses 10 seconds to substitute. The argument in support of the pitch was that it was a player safety issue, namely that tired players can be more susceptible to injury.

However, Air Force coach Troy Calhoun, the chairman of the committee said Tuesday that the panel was waiting for the evidence in support of the player safety angle. And that if there isn't any, the rule shouldn't be enacted.

"I think the only way it can or it should become a rule is if indeed it is a safety concern," Calhoun said. "And that can't be something that is a speculation or a possibility. I think there's got to be something empirical there, where you realize, yes, this truly is a health matter in the terms of not being able to get a defensive player off the field."

The proposal is set to be voted on March 6, and Calhoun said the end of the comment period was March 3. Calhoun's sentiments echoed what committee member Rogers Redding said following the proposal -- while player safety may be a legitimate concern, there's currently nothing convincing to support the idea.

"That's what you're waiting to see right now," Calhoun said. "You want to find out, is there certainly a -- I think it's got to be pretty resounding (in favor of the proposal). Otherwise it makes no sense to push a rule forward."

Many coaches have expressed their disapproval for the proposal, including Auburn coach Gus Malzahn, who said he's talked with Calhoun about it. Malzahn said that he's asked for the discussion to be tabled for a year. Nick Saban, the coach of Alabama, Auburn's main rival, was in the room during the discussion along with Arkansas coach Bret Bielema. Both coaches have brought up player safety concerns before in relation to uptempo offenses.

"There's absolutely zero evidence, documented evidence, that is hazardous on the pace of play, only opinions," Malzahn said Tuesday (via Al.com). "What I asked (Calhoun) to do is move this to next year where it is a rule-change year, that we can hear both sides and have a healthy debate on moving forward with the rules."

A tabling of the discussion doesn't look like it'll happen, so if the rule will pass in March, the data will need to be procured in the very near future. However, given the absence of data currently and Calhoun's comments, it's reasonable to think this won't move past the proposal stage unless a comprehensive and convincing report is created soon.

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Nick Bromberg is the assistant editor of Dr. Saturday on Yahoo Sports. Have a tip? Email him at nickbromberg@yahoo.com or follow him on Twitter!

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