At some point in Knoxville on Saturday, with no warning, every headset on both sidelines could go dead. Steve Sarkisian's coaches wouldn't be able to talk to each other. His play calls wouldn't reach Arch Manning. It could happen in the first quarter, in the fourth, or whenever the president moves to a different part of the stadium.

"Any time he enters the stadium or leaves the stadium or changes locations within the stadium, they cut off communication," Sarkisian said Thursday. "So you have to have a plan for that… and you get no warning."

That's the setup for the biggest Saturday of the young season: No. 1 Texas at No. 14 Tennessee, the SEC opener for both teams, at noon ET on ABC, with President Donald Trump in the stands, ESPN's College GameDay on campus and more than 101,915 fans dressed in orange and white. It's a lot for a September game. And it all puts the focus on one question: can Manning win a big game on the road?

The president, the checkerboard and a Manning homecoming

A White House official confirmed to USA TODAY that Trump will attend. It'll be his eighth college football game while in office across two terms, and his first since Indiana beat Miami for the national title in January. Tennessee is warning fans to expect Secret Service screening at every gate, extra perimeter checkpoints and heavy traffic. Gates open at 9 a.m. A flyover with two F-35s and a KC-135 follows the anthem. GameDay broadcasts from the lawn of Ayres Hall, its 13th visit to UT's campus, before moving inside for the final hour.

The politics tie in, too. On Thursday, the Senate voted 74-25 to invoke cloture on the Protect College Sports Act, the bill co-authored by Texas Sen. Ted Cruz, who got loudly booed at GameDay in Austin in Week 2. College football and Washington keep ending up in the same place this fall.

Then there's the family angle. Peyton Manning is expected to attend. According to CBS Sports, Arch will be the first Manning to play in Neyland Stadium since Peyton's last game there in 1997, and Arch says he's never been to Knoxville. Tennessee offered him early in recruiting. Sarkisian admitted he'd assumed Arch had visited. "Your last name's Manning," Sarkisian said. "Regardless of what you do, you're gonna get critiqued."

Arch's road problem

Here's what's hanging over the weekend. Manning has been excellent at home, including the 20-point comeback over Ohio State that sent Texas to No. 1. On the road, he's been a different quarterback. CBS Sports found that in his five true road games last season, he completed 57.7 percent of his passes with seven touchdowns and five interceptions. That stretch included trips to Ohio State and Georgia, but also to Mississippi State, Kentucky and Florida.

He's also coming off his weakest game of the season: 17-of-33 for 164 yards and two touchdowns in a 30-6 win over UTSA, which he called "ultimately not good enough." For the season, he's thrown for 664 yards, seven touchdowns and two interceptions. That's solid production that hasn't yet produced a signature road win.

Sarkisian isn't worried. "I don't know if I've ever been around a quarterback, maybe Matt Ryan, that prepares better than he does," he said, predicting Manning comes out "guns blazing." Manning sounded ready for it: "I'm definitely excited to play at a hostile environment, SEC road game. That's what it's all about."

The experts are split on this one. CBS Sports lists Texas as a 4.5-point favorite with a total of 55.5, and three of its nine experts picked Tennessee against the spread.

Faizon Brandon, age 18, against Will Muschamp

On the other side is a quarterback with nothing to lose. Faizon Brandon is Tennessee's first true freshman starter since Brent Schaeffer in 2004. He turned 18 in June and was in high school less than a year ago. He's thrown for 552 yards and six touchdowns on just 64 attempts, because the Vols have beaten Furman, Georgia Tech and Kennesaw State so easily he hasn't had to throw much.

Sarkisian's scouting report was blunt: "6-4, 225, he can run, he's got a rocket of an arm." He expects Josh Heupel to run the ball and take "six to eight shots a game down the field," the usual formula for protecting a young quarterback.

The matchup that could decide it is up front. CBS Sports points to communication problems on Tennessee's interior line. That's a real worry against a Texas front with 375-pound tackle Ian Geffrard and linebacker Rasheem Biles, and a defensive staff Sarkisian says can shuffle fronts because of its depth. Texas will be without defensive lineman Justus Terry, while edge Colin Simmons is probable after leaving the UTSA game at halftime. Tennessee's leading rusher, DeSean Bishop (286 yards, four touchdowns), is dealing with a hip injury but expected to play.

The Texas unknowns: Hutson and Smothers

Texas has two open questions of its own. Running back Hollywood Smothers, an NC State transfer with 198 yards and two touchdowns on 41 carries, was questionable on the first SEC availability report. Sarkisian joked about it and wouldn't elaborate. Offensive lineman Cole Hutson won another court ruling this week, but as of Thursday, Sarkisian said his availability would depend on a conversation with the SEC. The travel roster tops out at 74 players, compared with the "92 or 94" Texas took to Columbus last year.

Why Saturday is Manning's real test

Texas and Tennessee have met only three times, all in Cotton Bowls, the most recent a 36-13 Texas win on Jan. 1, 1969. They've never played at Neyland, which makes this matchup something new despite both programs' history. Tennessee is going for its fourth all-time win over a No. 1 team. Texas is playing its only true road game until November.

For Texas, that makes Saturday more than one game. The Ohio State comeback showed what this team can do at home. A win at Neyland, with the stadium full, a president watching and headsets possibly cutting out, would show it can do the same on the road. Sarkisian keeps telling his players to "be where your feet are" and appreciate the moment. Manning will need to do that when the headset goes quiet and he has to run the offense on his own.

If Manning wins here, the talk about his road struggles pretty much ends. If he loses, it gets louder. Either way, Saturday in Knoxville will tell us a lot about whether Texas deserves its No. 1 ranking.