The No. 6 Tennessee Volunteers (4-0) showed no love for the No. 15 Oklahoma Sooners (3-1) in their SEC debut. The Vols stormed into Norman like a frenetic tornado, defeating the Sooners 25-15 in a top 25 matchup, handing them their first loss of the season.

Though the 10-point difference may not seem significant, the play on the field told a different story. It was a defensive battle between the new SEC rivals, but while Tennessee managed to find the end zone a couple of times, Oklahoma didn’t score a touchdown until under nine minutes remained in regulation, only managing a field goal early in the first quarter before that.

By the end, Oklahoma football's only bragging right was that they were the first team to score a touchdown on Tennessee's defense this season. In fact, they scored two, but it was too little, too late. This was a game that could have been much different—or at least closer—if not for some very obvious mistakes that undoubtedly cost them.

So, who's most to blame for Oklahoma’s defeat at the hands of Tennessee in Week 4? Let's break it down.

The most obvious: Jackson Arnold

There’s a reason Jackson Arnold was benched in Saturday night's game against the Vols. Before halftime, Arnold had already been pulled from the game. In his short time on the field, he completed just 7 of 16 pass attempts for 54 yards and committed three turnovers.

One of his incompletions came on the Sooners’ opening drive when, on a fourth-and-2 at midfield, when head coach Brent Venables decided to go for it. However, Arnold failed to complete the pass. But that was the least of his troubles on the day.

On Oklahoma’s third drive, with the game still scoreless, Arnold threw an interception at the Sooners’ 47-yard line to Tennessee’s Jermod McCoy, who returned it to midfield. The Vols capitalized six plays later, taking a 3-0 lead they would never relinquish.

Then, with the Sooners down 10-3 early in the second quarter, their defense forced a Tennessee fumble from Nico Iamaleava, recovering it at the five-yard line. However, on the very next play, Arnold fumbled the ball back to Tennessee on a first-and-goal run at the six-yard line.

Later in the quarter, the Sooners’ defense once again forced an Iamaleava fumble inside Tennessee territory. But just like before, Arnold’s mistake—a backward pass resulting in another fumble—turned into a Vols touchdown, giving Tennessee a 19-3 lead heading into the half.

Since earning his first start in last season’s bowl game, Arnold has become a turnover machine. He now has nine turnovers in his five career starts, with five of those coming in his last three games. While true freshman Michael Hawkins Jr. looked shaky at times, he might give the Sooners a better chance of winning than Arnold moving forward.

Jovantae Barnes gives Tennessee a safety in the second quarter

Oklahoma Sooners running back Jovantae Barnes (2) looks up as Tennessee Volunteers defensive lineman Dominic Bailey (90) and linebacker Arion Carter (7) celebrate after a defensive stop during a college football game between the University of Oklahoma Sooners (OU) and the Tennessee Volunteers at Gaylord Family - Oklahoma Memorial Stadium in Norman, Okla., Saturday, Sept. 21, 2024.
© BRYAN TERRY/THE OKLAHOMAN / USA TODAY NETWORK via Imagn Images

If the first half for the Sooners wasn't bad enough with Arnold's multiple interceptions, Jovantae Barnes safety with under 10 minutes left in the half certainly didn't help matters.

The Sooners had just forced another Vols punt but they were pinned right inside their own five-yard-line. But an Oklahoma false start put the ball then at the two-yard-line. One play later, the Vols nasty defensive front got to Jenkins who couldn't escape the end zone, costing them two points to increase Tennessee's lead to nine.

Oklahoma's offensive line continues to struggle

As bad as Arnold's turnovers and Barnes' safety were, the Sooners got no help from their offensive line. After their loss to the Vols, Oklahoma now ranks 116th nationally in sacks allowed with 12. They also rank 113th in tackles for loss allowed, giving up 28, according to NCAA stats.

Tennessee's defensive line is one of the best in the country, so while Saturday's performance may have been somewhat expected, the numbers were still staggering. Tennessee recorded three sacks and racked up 11 tackles for loss.

With the schedule only getting tougher as SEC play continues, the Sooners need to figure out how to fix their offensive line—quickly.