Bill Callahan is a wizard when it comes to moving offensive linemen to different positions they've never played before.

Callahan, the Browns offensive line coach, has taught linemen at the college and pro level for four decades. He's been frequently tasked with helping a player with the daunting challenge of moving from the right side of the line to the left, and his most recent projects include Tyron Smith, Zack Martin and Brandon Scherff, all Pro Bowl players.

It's one of the hardest assignments a lineman might have to do — imagine a switch from being predominantly right-handed to left-handed in the span of a few months. Callahan knows all about it, however, and it'll be one of his biggest tasks for his first year in Cleveland.

Jedrick Wills Jr., the Browns' 2020 first-round pick, is undergoing that change right now. He played exclusively as a right tackle in his three seasons at Alabama, but he was drafted by Cleveland to play as a left tackle, where he'll protect the blindside of quarterback Baker Mayfield.

It's an uphill battle, and Callahan is confident he can do it. 

"When you watch a player on film, I think your takeaways are that this guy is a good player," Callahan said Thursday in a Zoom call with local reporters. "He's solid, he has athletic ability, but with Jedrick, it was a little different in that you could feel him on film. He came alive on tape. You got excited about what he was doing throughout the course of the game."

Wills is 6-foot-4 and 312 pounds. In his final season as a junior at Alabama, he allowed just one quarterback sack, 3.5 quarterback hurries and was the biggest force in the offensive line, which ranked third nationally and allowed just .92 sacks per game. He also has durability and started his final 28 games with the Crimson Tide.

Yes, that was all done from a position that he'll no longer play in Cleveland, but it takes more than sheer talent to switch from one end of the line to the other. Some of Callahan's best projects prove it.

After the draft, many analysts compared Callahan's task with Wills to that of Smith, a player whom Callahan switched from right tackle to left tackle with the Dallas Cowboys in 2012. Smith, who's still with the Cowboys, is now one of the best left tackles in the league. He's accrued seven Pro Bowl appearances and was named to the Pro Football Hall of Fame's All-Decade Team.

Callahan, however, compared Wills to another one of his former players: Barry Sims. After a stint with the Scottish Claymores in the now-defunct NFL Europe League, Sims signed an undrafted free agent deal as a training camp pick-up for the Oakland Raiders in 1999. He was nothing more than roster depth expected to be shed when training camp ended.

Jon Gruden, who was in his first stint as the Raiders coach, didn't want to keep Sims on the roster at left tackle despite a key injury that thinned the depth at the position. Callahan, the offensive line coach, urged Gruden for a few more days of work with Sims. He had potential at left tackle, and Sims believed he could coach him up to be a mainstay at the position.

Callahan was right. Sims made the cut and started 10 games rotating between left tackle and both guard positions. He finished his career 12 seasons later after becoming a reliable right and left tackle for the Raiders and San Francisco 49ers.

It worked because Sims had the desire to play anywhere. He had an unquestionable athletic ability, too, and both those traits are what Callahan sees in Wills.

"Jedrick reminded me of Barry, and he could make that switch easily because of his athleticism," Callahan said. "He's got these intangibles that show up in tangible ways on film. You watch him finish — the detail, the technique. You watch his consistent effort and stamina throughout the course of the game from start to finish, and I think that was the appeal for me. The willingness is number one. You have to want to go over there." 

Callahan's job with Wills is much different, though. As the NFL awaits solutions to safely return to practice during the COVID-19 pandemic, Callahan has no choice but to work with Wills through virtual communication. 

So far, Wills has focused on the basics. Callahan is teaching Wills how to position himself in the left-handed stance, and the two have been exchanging videos with small tweaks about hand and foot placement. They've also reviewed video of former tackles Callahan has coached.

"It's been really positive," Callahan said. "He's staunch for information. I'm eager to, at some point, get on the field with him."

That next step will be important for Wills. Muscle memory is one of the most vital skills a lineman will need to master a new position, and that's only attained through trenchwork against the defense. No one knows when any NFL team will be able to safely practice that.

Who might Wills line up against when the Browns finally return to practice? Well, if he receives first-team reps, it'll be with Myles Garrett, fresh off a season in which he made 10 sacks in 10 games.

The Browns might not have Wills immediately compete against one of the top defensive ends in the league when on-field practices resume, but that's the expectation Callahan has at some point before Week 1. Callahan didn't leave any doubt in his answer about whether Wills will be an immediate starter for the Browns.

"I think whenever you draft a player as high as we drafted Jedrick, I've always felt that you got to plug him in and play him immediately," Callahan said. "That's why you drafted him. That doesn't concern me, scare me, bother me in any respect. I'm quite confident he's capable of being there at left tackle."

Even though they're not on the field yet, Callahan has plenty of time to teach Wills all the key movements and skills of the position. He knows Wills has the drive to learn them, too. So far, he's checked all the boxes Callahan typically has in a player undergoing a position change.

With Callahan, there's plenty of reason to believe the progress will only ascend.

"Throughout my career, I've had a lot of guys who I've mixed and matched and moved around," Callahan said. "Some guys can make the switches, and some guys can't. It's always fun. If they want to do it, they'll make the switch.

"(Wills) has absorbed all the content we can give him, and he wants more. I'm really excited about him."