Vance Joseph and the Broncos’ coaching staff gathered in Mobile, Ala., last winter to lead the North Team at the Senior Bowl for an opportunity to coach and evaluate among the nation’s top NFL prospects.

Joseph organized several practices with a 12:30 p.m. start time.

The quarterbacks, though, arrived well before noon.

Baker Mayfield’s idea.

“He grabbed the quarterbacks and they had an hour before we got there (with) footwork and taking snaps from center,” Joseph said. “Those things that he wasn’t very good at, he worked on every single day. You could see it right away that he wants to be a great player.”

Few predicted the Browns would select Mayfield with the No. 1 overall pick four months later and even fewer expected Cleveland’s playoff chances to be mathematically alive with three games left at 5-7-1. But little doubt surrounds Mayfield’s star potential as he faces off against his former Senior Bowl coaching staff Saturday night at Mile High. The Broncos are at full attention.

“When you look at him on film you’re like, ‘This guy is a baller,’” safety Su’a Cravens said. “He goes out there and doesn’t care what any defense does. He has that swagger of: ‘I’m going to make these throws. Go ahead and treat me like a rookie if you want to.’ ”

Mayfield’s transition from Oklahoma Sooners’ Heisman-winning quarterback to No. 1 pick took a significant step at the Senior Bowl with ESPN calling Mayfield, “the most comfortable running the offense, and he also showed the most consistency with the biggest variety of throws.” The Broncos, one month after signing quarterback Case Keenum to a two-year, $36 million deal, brought Mayfield in for an April workout at UCHealth Training Center including dinner with team brass. However, any possibility of landing Mayfield ended with the Browns’ top selection.

“I really enjoyed working with all of those (Broncos) guys on the offensive side and Coach Joseph,” Mayfield said. “How detailed they were, how they wanted to get us better and help us learn different things. To kind of give us a new perspective on a different offense that we hadn’t worked with before. I really enjoyed it.”

Added Joseph: “I knew that he had the arm talent to (be the No. 1 pick) and the football IQ. After the first (Senior Bowl) install, he could’ve taught the offense.”

Mayfield’s rookie season can be broken in two parts: before and after the firing of coach Hue Jackson and offensive coordinator Todd Haley. Under the old regime, Mayfield completed 58.3 percent of his throws at 6.6 yards per attempt, eight touchdowns, six interceptions and a 78.9 quarterback rating. With interim coach Gregg Williams and Freddie Kitchens running the offense, Mayfield’s completion percentage is up to 73.2 with 9.2 yards per pass, 11 touchdowns, four interceptions and a 114.5 passer rating.

An uptick made possible with increased participation from Mayfield in game-planning, Williams said, with scheme and play-calling directly reflecting Mayfield’s strengths utilizing weapons like running back Nick Chubb (5.3 yards per carry and eight touchdowns) and wide receiver Jarvis Landry (69 receptions for 791 yards). It has given Mayfield increased confidence and flexibility making calls at the line of scrimmage, plus adding shades of what made him must-see TV in college.

“I try and give my perspective on some different things, a little twist or turn here and there of what I’ve done in the past and how to teach it to the receivers,” Mayfield said. “Those are the things that I do, but we’re not running just our Oklahoma offense, it’s a combination of what I’ve done in the past, what Freddie Kitchens does and our old system we had installed at the beginning of the year.”

Mayfield’s moxie has impressed many in the Broncos’ locker room.

“I’ve always liked Baker, even in college,” running back Phillip Lindsay said. “You’ve got to admire someone like that and especially at the quarterback position. I can’t wait to talk with him after the game, but during the game, he’s gonna have to watch out because (Bradley) Chubb, Von (Miller) and the defense, they’re not playing around.

“It’s about that time to go out there and get us a win.”