NORMAN — In just three weeks, there's been a noticeable change in Oklahoma's offense.

That change? There's a more confident version of Jackson Arnold behind center, and it's a version of the true sophomore that wasn't on the field through the first four weeks of the season.

Wide receiver JJ Hester even had a specific word to describe Arnold's new demeanor.

"He's definitely just playing more confident," Hester said Tuesday. "I'm happy for him. I like to see him play like that. The kids call it 'aura' nowadays. And so he has a lot of aura going off. I need to get some of that.

"Everybody wants a piece of it. Just like granny's cake. Everybody wants a piece of Jackson, I guess you could say."

The basic stats back up Hester's theory.

Through the first four weeks, Arnold was inaccurate, lacked explosiveness and was turnover prone. Arnold acknowledged that the pressure of being Oklahoma's starting quarterback was overwhelming and as a result — along with significant injuries on the offensive line and at receiver — the Sooners' offense struggled.

But since Arnold replaced Michael Hawkins in the first quarter against South Carolina, there's been a big change in his confidence and his effectiveness. Here's a look the numbers for Arnold's first four weeks compared to his last three games:

The advanced stats show real improvement, too. Before he was benched, Arnold averaged just 8.81 yards per completion. Since returning against South Carolina, he's averaged 11.5 yards per completion and has connected on more explosive passing plays. That has shown up in the 58-yard touchdown pass to Brenen Thompson against South Carolina and his 90-yard touchdown to JJ Hester last weekend — the longest passing play in the history of Gaylord Family Oklahoma Memorial Stadium.

There's a big reason why Arnold has felt more confident — the elevation of interim co-offensive coordinator Kevin Johns.

"The biggest thing was not playing carefree, but I had nothing else to lose, just having that edge and playing like that has really let me see things better and just play more comfortable and more loose," Venables said. "And coach Johns, since he got promoted, he's been big about us being efficient as quarterbacks. Whether that's getting through reads quick and boom, taking off, not sitting in the pocket too long, or just even just getting completions. Like today in practice, he was harping about us in seven on seven about not throwing an incomplete ball. He just wants us to create completions and be efficient.

"The things that he teaches us and how to be efficient and even with different footwork drills that he does with us, is I've seen improvement so far. Even through two to three weeks of my pocket movement getting to progressions quicker and easier, he's really helped us so far."

His running ability has been particularly helpful, too. Not including the yards lost from sacks, Arnold has run the ball 34 times for 176 yards while averaging nearly 5.2 yards per carry.

That has had an impact on Jovantae Barnes, who rushed for over 200 yards against Maine as he's produced a late-season resurgence.

"I'm just happy to see him back out there and have a lot more joy and just be happy to be out there with his guys," Barnes said. "I've said this before, Jackson didn't have a sad face. Just brought energy to the team. I was excited for that because that's what I was looking for."

OU coach Brent Venables attributes that success to his approach following his benching against South Carolina.

"He had some of his best practices that he’s had," Venables said Tuesday. "Said it at the time and looking back he’s continued to be that way...His ability to stay focused and to stay positive in his own mind and just go to work, and that’s what he chose to do, that helped him continue to improve and get better. This is a young player that has only started a handful of games in college.

"So, the development piece requires that you continue to stay consistent in your process, in how you watch film, how you go to practice, how you take criticism, how you handle adversity in practice, because it’s real... He chose to, instead of feel bad for himself and sorry for himself, instead of point the fingers and be paralyzed in the moment, he chose to grow and improve and get better and take ownership of all of his work."

Now, Arnold has an opportunity to continue that confidence against Missouri.

The Sooners travel to Columbia this weekend (6:45 p.m. SEC Network) for a pivotal road test against a Missouri team that has dropped two of its last three games. Missouri's passing defense has been stout this season, ranking 10th in yards allowed while ranking ninth in passes allowed of 20 yards or more. But they've been vulnerable against the run, ranking 54th nationally in rushing yards allowed.

For the Sooners to generate some momentum as they head into the final part of the season, and snag that much-needed sixth win to become bowl eligible, they need Arnold to continue finding his rhythm.

"Hopefully we just keep on building momentum," Arnold said. "Keep on making those explosive plays. They keep our offense going."