— The final Saturday of September means conference play. Lots and lots of conference play. It won’t be too late in November to erase a bad performance, but it’s never too early for a great first impression, either. Take heed, BCS bowl hopefuls and would-be Heisman Trophy candidates. Here are five things to watch:

1. Big 12 drama – ON the field!
Conference headlines have been dominated by a four-school shuttle to the West Coast (um, not so fast). There has been talk about coming and going, about the ousting of a commissioner, about neutering a flammable network, about political wrangling and bad blood.

Now the Big 12 discussion might actually revolve around a football game.

It’s No. 7 Oklahoma State (3-0) at No. 8 Texas A&M (2-0). Which one will become the biggest challenger to top-ranked Oklahoma? We’re about to find out.

The Cowboys and Aggies are ranked in the top 10. They are contenders for BCS bowl berths. In recent memory, it could be the largest Big 12 game (at least from the old South Division side) that didn’t involve Oklahoma or Texas.

Off-field issues can’t be completely eliminated. With Texas A&M almost certainly headed to the SEC — a decision that has jump-started the current environment of conference uncertainty — the Aggies should be an emotional target against their (for now) Big 12 rivals.

Mostly, defensive backs have been the biggest target in the Oklahoma State-Texas A&M series. The games have been high scoring and unpredictable, including last season’s 38-35 Cowboys victory that wasn’t a work of art. There were eight interceptions. Neither team was ranked. It looked like an offensively entertaining game between two teams that didn’t seem headed to a championship season.

Now it’s a battle of top 10 teams.

And potentially, it’s still very entertaining.

The Aggies began their march to the Cotton Bowl since installing Ryan Tannehill at quarterback. He has won seven of his eight starts. Meanwhile, the Cowboys continue to thrive with Billy Weeden at quarterback and Justin Blackmon at wide receiver.

Both the Cowboys and Aggies have the look of 10-victory teams, programs that can give a good run to the Sooners. Which one will become Oklahoma’s chief challenger? We’re about to find out.

2. Who’s for real?
At the bottom of this week’s Associated Press Top 25 rankings, there are five brand-name programs, all at 3-0. But are these guys for real?

* Clemson (hosting Florida State) — Back-to-back victories against the defending national champion (Auburn) and a Top 10 preseason team (Florida State) would make the Tigers a for-real program in my eyes. Clemson has a terrific pitch-and-catch combination with sophomore quarterback Tajh Boyd and freshman wide receiver Sammy Watkins. One more thing: Florida State hasn’t won in Death Valley since 2001.

* Michigan (hosting San Diego State) — It’s the Brady Hoke Bowl with the new Michigan coach facing his old program. It’s going to be a more difficult game that even Hoke anticipates because of the emotion on both sides. Even if the Wolverines advance to 4-0, and even if quarterback Denard Robinson has another fabulous afternoon, I’m not ready to declare Michigan as a for-real program just yet. Very soon, the schedule will shift into unforgiving mode.

* USC (at Arizona State) — The Trojans are one year away — at least — from serious contention for a division title (USC is ineligible for the inaugural Pac-12 title game). The league schedule will soon head uphill, so we need to see more before proclaiming the Trojans as a for-real team.

* Illinois (hosting Western Michigan) — Ron Zook’s ballclub collected a very nice non-conference victory against Arizona State and getting to 4-0 against the Broncos should be very achievable. I’m calling the Fighting Illini as a “for-real’’ entry. Looking at the schedule, I see an 8-4 finish and that would be a major positive for Illinois, which was picked for fifth in its six-team division.

* Georgia Tech (hosting North Carolina) — This is definitely a counterfeit 3-0 mark for the Yellow Jackets with victories against Western Carolina, Middle Tennessee State and Kansas. The back-to-earth journey begins on Saturday.

3. Don’t sleep on the Hogs
In the SEC West, probably the most powerful division in college football, we’re all waiting for Nov. 5, when No. 2 LSU travels to No. 3 Alabama for what could be an unbeaten vs. unbeaten matchup to decide conference superiority and, perhaps, a route to the BCS Championship Game.

At least that’s how it looks on paper.

Suggestion: Don’t overlook the Arkansas Razorbacks.

You can’t bet Alabama won’t do that. The Crimson Tide (3-0) hosts No. 14 Arkansas (3-0) on Saturday. The Razorbacks love being under the radar and they relish all the LSU-Alabama talk. Arkansas, which was seemingly dismissed after losing star running back Knile Davis to a year-ending injury before the first snap, could create the first season’s seismic shift by stunning the Tide.

For those who enjoy X-and-O matchups, this is an ultimate confrontation. Alabama’s Nick Saban is excellent at designing a defensive concept and putting his players in the right positions to thwart an offense. Arkansas’ Bobby Petrino is one of the game’s top offensive minds, knowing exactly what it takes to move the ball.

Could it be that the SEC’s game of the year will actually occur about five weeks earlier than expected?

4. Almost heaven?
LSU coach Les Miles made it sound like his team was visiting a theme park.

“We’re looking forward to going to Morgantown,’’ Miles said. “They say it’s a wonderful place to play. They say it has a tremendous atmosphere, very much like an SEC opponent.’’

Nice try.

West Virginia’s home stadium isn’t exactly Disney-esque for opponents. It’s regarded as one of the most hostile environments in college football.

With the Tigers visiting for the first time, with West Virginia fans having extra time to (ahem) prepare for this Saturday night game, the Mountaineers have one of the biggest opportunities in program history.

LSU’s defense looks rugged and uncompromising. But West Virginia quarterback Geno Smith might be the Big East’s best slinger.

I’ll say this for LSU. If the Tigers go into October with victories against Oregon, Mississippi State and West Virginia — all away from Baton Rouge — they should be voted as the nation’s No. 1 team.

No question.

5. Rush to glory?
In the last 10 seasons, only one Heisman Trophy winner has been a running back (Alabama’s Mark Ingram, 2009).

So in a year that includes quarterbacks such as Stanford’s Andrew Luck, Boise State’s Kellen Moore, Wisconsin’s Russell Wilson, Michigan’s Denard Robinson and Baylor’s Robert Griffin III, can a running back already be considered a favorite?

You bet.

South Carolina sophomore running back Marcus Lattimore is superb. Through three games, he has rushed for 534 yards and seven touchdowns, including a 246-yard, three-touchdown performance against Navy last week.

Lattimore and the Gamecocks (3-0) will continue to get attention as the victories mount. South Carolina hosts Vanderbilt (3-0), suddenly no easy touch, on Saturday.

“You’ve got a tailback there that anybody in college or the NFL would want him on their team,’’ Vanderbilt coach James Franklin said.

Yes, Lattimore is that good — and that important to the Gamecocks. If South Carolina gets deep into October with a winning record, there will be a case to be made — a very good case — in the matter of “Lattimore for Heisman.’’