BIRMINGHAM, Alabama -- Dave Hart arrived from Alabama as Tennessee's new AD knowing the obvious: Alabama and Tennessee must continue playing football every year.

"The history that rivalry has produced is unparalleled in my mind," Hart said. "I know Mal (Moore, Alabama's AD) feels exactly as I do. I feel strongly we can keep it and hope it can go back to the Third Saturday of October where it belongs. It would be a nice cherry on the top if all that would unfold."

Preserving Alabama-Tennessee is on the minds of many people -- OK, we get it, not Nick Saban's -- as the Fourth Saturday of October blends into Missouri's potential arrival in the SEC. It would be an upset if the game disappeared. The SEC surely understands its historical significance.

But if Missouri comes -- the school's board of curators has meetings today and Friday that could start the application process with the SEC -- the options become limited on how to keep Alabama-Tennessee and create balanced divisions and schedules.

Jon Solomon is a columnist for The Birmingham News. Join him for live web chats on college sports on Wednesdays at 2 p.m.

One option is to put Missouri in the East Division so Alabama-Tennessee remains a permanent cross-divisional game. Another is adding a ninth SEC game and play six divisional games, two permanent partners and one rotating cross-divisional game.

"The (Alabama-Tennessee) decision will come from a lot of vetting and conversation," Hart said. "We have a lot of conversations ahead before we get into that conversation. We're in the infantile stages of how to figure out what's the best option to make 13 work. While it's premature, the question is a fair one."

Alabama-Tennessee remains very significant to college football, although the rivalry isn't what it was 20 years ago due to divisional play and streaks of domination by one team, former SEC Commissioner Roy Kramer said.

"There are only about three of those in the conference: Auburn-Alabama, Auburn-Georgia, Tennessee-Alabama," Kramer said. "I would think you would try as hard as you possibly can to maintain those kinds of rivalries. When we did expansion 20 years ago, that was one of the factors we looked at very significantly when looking at scheduling and divisional alignment. They may have to alter that to make it work."

Very few decision-makers will want one possible option: add a ninth SEC game. Coaches wouldn't like unbalanced home-and-away SEC schedules and another challenging game. ADs wouldn't like losing gate revenue every other year. Programs that use easy nonconference games to be bowl-eligible might hate it the most.

But the Pac-12 and Big 12 play nine games, and the Big Ten will go to nine in 2017. Growing bigger isn't a good excuse to end Alabama-Tennessee, which started 110 years ago and has been played annually since 1944.

Unfortunately, rivalries are becoming expendable these days. Oklahoma-Nebraska, Texas-Texas A&M, West Virginia-Pittsburgh and Missouri-Kansas have either disappeared in football or soon could vanish. In basketball, Syracuse now risks losing rivalries with Georgetown and St. John's by going to the ACC.

It's true new rivalries can be created. Without realignment, Kramer argues, there wouldn't be SEC rivalries/traditional games such as Arkansas-LSU, Tennessee-Florida and South Carolina-Georgia, and now Nebraska-Wisconsin in the Big Ten.

Alabama-Tennessee has been off the national and SEC radar for a while. Both teams haven't been ranked when playing this game since 2005. Saturday marks the 12th straight game in the series in which Alabama or Tennessee enters with more than one loss; that only happened 11 times from 1979 to '99.

Yet 45 percent of the all-time Alabama-Tennessee games have been decided by one possession. That's a better rate than Alabama-Auburn (41 percent) and only slightly behind Auburn-Georgia (46 percent).

Nick Saban has routed the Vols by an average of 19.3 points in four wins. But the unforgettable 12-10 nail-biter in 2009 -- call it Lane Kiffin's rare gift to the SEC -- demonstrates why this series needs to be protected.

Alabama-Tennessee, the rivalry of Bryant and Neyland, produced an unlikely road challenge by the Vols that ended with Terrence Cody's big paw preserving a national championship season.

Television sets in Texas and Missouri pay the bills. But rivalries bank the equity in the hearts and minds of viewers.

Write Jon at jsolomon@bhamnews.com. Follow him at twitter.com/jonsol.