Joe Montana doesn't know if he would have ever worn No. 0 in the NFL if he had the option.

When he was drafted by the San Francisco 49ers out of Notre Dame in the third round of the 1979 NFL draft, he tried to keep his college number, but it wasn't to be.

"When I got to the NFL, how I got my number was kind of hilarious. I was trying to get my college number and the old equipment manager, he goes, ‘Here, here’s your number,'" he told USA TODAY Sports. He donned No. 16 for the majority of his Hall of Fame career. "I go, ‘I’d like to get No. 3.’ He goes, ‘No, here’s your number.' That’s it."

In March, owners approved the Philadelphia Eagles' proposition to allow all players except offensive and defensive lineman to wear the No. 0.

"I think it’s great," Montana said of the change. "... Colleges have always let people, like you see defensive ends wearing No.9, you never saw that (before). The NFL is starting to relax a little bit."

Montana is part of a campaign that takes advantage of the many marketing opportunities that come with the hollow digit. He is partnering with Cincinnati Bengals passer Joe Burrow to promote Guinness 0, the Irish brewery's non-alcoholic product. Montana, who has been a spokesperson for Guinness since 2020, said Guinness 0 does not compromise on taste.

 "You couldn’t tell the difference," he said.

In the first spot, called "Unsung Zeros," the two quarterbacks run into each other in a locker room where Burrow is wearing a No. 0 branded jersey. Montana asks him if he is going to change his playing number from No. 9, to which the Pro Bowler has a clever response.

Guinness 0 is releasing replica jerseys from the campaign (both a black and white design) for fans to purchase at Guinness0Jerseys.com with proceeds going to The Joe Burrow Foundation. The charity provides support for underprivileged communities in Cincinnati and Baton Rouge, Louisiana, where Burrow attended college at LSU.

Montana explained how the Bengals star's heart for giving back shows his character.

"I think so many people get to this level, like he has so quickly, and then forget about all these things that are important to other people outside," he said, "and the way that you can really reach out and help and have the ability to do that. That speaks I think so highly of him and his integrity.

"And then watching him play, it’s just fun. He’s got a great ability, he showed it in college and he just carried it over here into the NFL. He’s gonna be one of those guys that’ll be around for a long time and a lot of fun to watch."

The ad also serves as a bridge between generations.

"I’m not a spring chicken," Montana laughed. "So it’s great to have someone on the other side to be able to reach those younger folks out there."

Per league rules, active NFL players can't promote alcoholic beverages, but the rule has led to creative brilliance like Patrick Mahomes' Coors Light campaign where he advertised flashlights and proceeds went to his 15 and the Mahomies charity.

As the game of football evolves, Montana pointed to quarterbacks like Mahomes and said they have continued to show the essential nature of the role. Quarterbacks have increasingly become running threats, partially leading to the devaluation of the traditional running back position.

But Montana said the success of teams like the Kansas City Chiefs, who won Super Bowl 57 for their second championship in four years, and the Josh Allen-led Buffalo Bills, who have made the playoffs every year except his rookie season, as evidence for how the quarterback position is essentially different. Last season, both Mahomes and Allen were the second-leading rusher on their respective teams, but also threw for 5,250 yards and 4,283 yards. Mahomes was named the 2022 NFL MVP.

"I think still, when you look at the teams who are successful in the league, (they) still run the football and not with their quarterback as much as a running back," he said, adding that quarterbacks typically are "not built like a running back."

On Mahomes: "He can run, he can do everything, but the majority of the time, but the majority of the action’s happening in the pocket."

On Allen: "Same thing. He can run like crazy, too. He’s a big guy."

He said that quarterbacks who run a lot tire more easily and used the example of Super Bowl 47 when Colin Kaepernick, who had 62 rushing yards in the game, threw three incomplete passes and failed to get a touchdown from the 7-yard line late in the game. The 49ers lost to the Baltimore Ravens, 34-31.

"The guy ran the ball so many times and then he had to make three throws in the end zone to win the game," Montana said, "and it didn’t happen. ...

"If you want the team to win consistently, the quarterback plays mainly in the pocket."