Here’s what we know: LSU’s Leonard Fournette and Alabama’s Derrick Henry will both be fabulous Saturday, as they are two of the elite running backs in the nation and likely stars at the next level.

But here’s what we don’t know: Just exactly what we’ll get out of LSU’s Brandon Harris and Alabama’s Jake Coker at the game’s most important position, as each quarterback has put his fair share of good and bad on tape.

While they’ll never be on the field at the same time in Tuscaloosa, whoever outplays the other probably trots back to the locker room victorious — one step closer to the College Football Playoff, too.

Harris, a 6-foot-3, 206-pound sophomore from Bossier City (La.) Parkway High School, is second in the SEC with a passer efficiency rating of 153.9, although he’s attempted (128) and completed (75) fewer throws than anybody else in the top 10.

That’s perfectly understandable with Fournette — everybody’s frontrunner for the Heisman Trophy — lining up in the backfield, but Harris deserves credit for his perfect touchdown-to-interception ratio of 9-to-0 through seven games.

Following forgettable performances against Syracuse (8-of-16 passing, 1 TD) and Eastern Michigan (4-of-14, 0 TDs), he was sharp facing South Carolina, No. 11 Florida and Western Kentucky (42-of-67, 7 TDs combined).

According to Brent Holloway, who covers LSU for Saturday Down South, even though Harris is far from a surgeon with the football, he hasn’t been forcing it into coverage.

“You can see why Harris was hyped as a recruit,” Holloway said. “He’s a good athlete with a strong arm, and he throws a pretty ball. He can be erratic with his accuracy at times, but he hasn’t made bad decisions. His ability to avoid turnovers will be crucial to the Tigers’ chances on Saturday.”

The key to moving the chains consistently against a devastating front seven like Alabama’s could be Harris’s legs, not his arm, which in turn helps his tailback.

“He doesn’t run a ton, but it’s part of his arsenal and could serve him well this week when Alabama gets pressure,” Holloway said. “I also wouldn’t be surprised to see (offensive coordinator) Cam Cameron call a few more designed runs for Harris this week to keep some of the heat off of Fournette.”

Coker, a 6-foot-5, 232-pound senior out of St. Paul’s Episcopal School in Mobile (Ala.), didn’t throw a touchdown pass his last two times out, although he did direct a game-winning drive late in the fourth quarter to squash an upset bid by Tennessee.

It has taken Coker quite some time to finally be the big man on campus, as he was beaten out in 2013 for the starting job at Florida State by Jameis Winston — no shame there, as Winston won the Heisman and a national championship.

After graduating early and transferring to Alabama, he was unexpectedly handed a clipboard again in 2014 as the backup to Blake Sims. Stan Chrapowicki covers Alabama for Saturday Down South, and he believes Coker is only now beginning to spread his wings in better-late-than-never fashion.

“In watching Coker this season, I get the sense he is still very much a game manager for Nick Saban at Alabama, which is easy to be when you have a back as talented as Henry lining up behind you,” Chrapowicki said. “But the truth is Coker is evolving into a winner, and his 74-percent completion rate during the month of October is a big reason why Alabama is rolling going into its showdown with LSU.”

Nobody expects the Tide to shut down Fournette, just like nobody expects the Bayou Bengals to put shackles on Henry, which means one big play — or one crucial mistake — from Harris or Coker could be the difference at Bryant-Denny Stadium.

“Both these teams’ strengths are so similar, they cancel each other out,” Chrapowicki said. “Ultimately, Saturday night’s game is in the hands of the QBs.”

The Crimson Tide possess the premier rushing defense in the conference, giving up just 78.5 yards per game, while the Tigers are second in that crucial category (93.7).

That may not matter much to Fournette, who ran 31 times for 180 yards and two TDs against a Florida run D currently No. 3 in the SEC behind Alabama and LSU. Likewise, Henry totaled 50 carries for 222 yards and two scores combined facing Ole Miss and Arkansas, which both have a run defense in the top half of the conference.

As a result, Harris and Coker will surely benefit from facing a ton of man-to-man and single-high-safety coverage — plays are there to be made, unquestionably.

“Let’s all be honest: Both of these guys rely heavily on their run game,” said former South Carolina quarterback Stephen Garcia, an SDS contributor. “With Henry and Fournette being the top two running backs in the country, there’s a reason for that reliance. When the run game is effective, the play-action passing attack is as well. I used to have that same type of game plan sometimes when I had Marcus Lattimore behind me.”

Signal callers get too much credit for wins and too much blame for losses, but Harris and Coker signed up for such treatment the moment they lined up under center.

“Look for ‘Bama and LSU to stack the box and force these quarterbacks to beat them throwing the ball,” Garcia said. “This will be a hell of a matchup, and I can’t wait to see how the game unfolds.”