Former NBA star Deron Williams confirmed Tuesday he will face former NFL star Frank Gore in a four-round boxing match.

Adrian Wojnarowski of ESPN first reported the agreement.

The bout will take place on Dec. 18 in Amalie Arena in Tampa, Florida, as the undercard of Jake Paul vs. Tommy Fury.

Ariel Helwani also confirmed the details of the fight, noting it will take place at 215 pounds with four, three-minute rounds. 

Williams, 37, was a three-time All-Star during his NBA career before retiring after the 2016-17 season. The 38-year-old Gore was a five-time Pro Bowler across his 16 years in the NFL.

Though Gore is not officially retired, he is yet to sign with a team in 2021 after playing 15 games (14 starts) with the New York Jets last year.

Not every transition into boxing has been successful—as Nate Robinson can tell you—but both of these athletes have experience training in combat sports.

Gore explained in September that he has been working on a transition to boxing.

"I've been training for both—football and boxing," he told Ian Rapoport of NFL.com. "I've always loved boxing, so that's what I've been doing. And we're trying to make a fight happen. If we do that, you'll see me in the ring."

Williams was a state champion wrestler in high school and is a co-owner of Fortis MMA gym in Dallas. He discussed how his background will help in the upcoming bout, via Brent Brookhouse of CBS Sports:

"Combat sports have been a part of my life since my youngest days. Before I was a basketball player, I was a wrestler. Since 2015, I have had the privilege of owning an MMA gym, and through that I have trained in various martial arts to stay active. Over the last year, I've been waiting for the right opportunity to translate my training into a professional debut. I'm making that happen on Dec. 18 against Frank, one of the physically strongest NFL players in history."

The 6'3" Williams could use his height advantage over Gore (5'9") in addition to his fighting background.