Fanatics Flag Football Classic features far different rules than NFL players — and fans — are used to

Kyle Shanahan thought he knew what he was getting into.

The 49ers coach has been around football his entire life. He played it in college. And as a toddler, he watched his dad hoist a Lombardi Trophy twice.

But after signing up to manage a team in the Fanatics Flag Football Classic, he quickly learned he didn’t know a lick about the flag iteration of his favorite sport.

Niners coach Kyle Shanahan is coaching the Wildcats team Saturday at the Fanatics Flag Football Classic. John Salangsang/Shutterstock

“Once we saw a couple games,” the 46-year-old said Friday, “I realized I didn’t know what I was getting into. And I had to figure this out really fast.”

Many who tune into Saturday’s showcase at BMO Stadium will almost certainly have a similar experience to San Francisco’s sideline manager.

The field is only 50 yards long and 25 yards wide. The action is 5-on-5, not 11-on-11. And no tackling is allowed.

“We can’t take a play from our game and run it in this game,” Shanahan said. “It’s totally different.”

The event will pit three teams against one another in a round-robin tournament. Two of the rosters — dubbed Wildcats FCC and Founders FCC — will comprise current and former NFL players. The third squad in the mix is the U.S. men’s national team.

Each game will feature two 15-minute halves with a running clock.

All drives will start at the 5-yard line, and quarterbacks will have just four downs to reach midfield. If they make it, they’ll receive an additional four downs to get to the end zone.

Signal callers will have seven seconds to get rid of the ball once it is snapped, though if it’s handed off, a flag pull is the only thing that can kill the play.

Penalties, such as false starts, illegal contact and pass interference, will be called.

NFL legend Tom Brady is captaining the Founders team Saturday at the Fanatics Flag Football Classic. Getty Images for OBB Media – FANATICS STUDIOS

Like Shanahan, Tom Brady, who’s captaining the Founders, said preparation for the contest has been quite the adjustment — though the biggest thing he’s concerned with is the amount of real estate his wide receivers will have to work with.

“A lot of the crossing routes, we were trying to get separation,” Brady said, “and yesterday, guys were just running out of bounds.”

Nonetheless, Brady, Shanahan and several of the other NFL participants said this week they were eager to see how they’d adjust once play begins at 1 p.m. PT.

“I feel like we’re doing 1-on-1 with 10 people out there on a tennis court,” Shanahan said. “So, I really don’t know what’s going to happen.”