Chris Colbert has a much younger, fresher opponent for his upcoming title defense than Yuriorkis Gamboa.

BoxingScene.com has learned that featherweight contender Tugstsogt Nyambayar has agreed to move up to the junior lightweight division on short notice to challenge Colbert on July 3. Nyambayar will fight for Colbert’s WBA interim 130-pound championship in the 12-round main event of a Showtime Championship Boxing broadcast from Dignity Health Sports Park in Carson, California.

Nyambayar is a featherweight, but the 28-year-old Mongolian is 11 years younger than Gamboa. The Cuban born-Gamboa suffered rib and heel injuries while training in Las Vegas recently and withdrew from his scheduled fight with Colbert late last week.

In his most recent appearance, Nyambayar (12-1, 9 KOs) beat Cobia Breedy (15-1, 5 KOs) by split decision in a 12-round featherweight fight September 19 at Mohegan Sun Arena in Uncasville, Connecticut. The 2012 Olympian’s lone loss as a professional came against WBC featherweight champion Gary Russell Jr. (31-1, 18 KOs), who beat Nyambayar by unanimous decision in their 12-rounder in February 2020 at PPL Center in Allentown, Pennsylvania.

The 39-year-old Gamboa has won world titles in three weight classes, but the 2004 Olympic gold medalist is well past his prime.

Unbeaten WBC world lightweight champ Devin Haney (26-0, 15 KOs) dominated Gamboa in the Cuban-born boxer’s most recent fight. Gamboa lost all 12 rounds to Haney on two of three scorecards November 7 at Seminole Hard Rock Hotel & Casino in Hollywood, Florida.

Gervonta Davis (24-0, 23 KOs) stopped Gamboa in the 12th round of Gamboa’s previous fight, which took place in December 2019 at State Farm Arena in Atlanta.

Brooklyn’s Colbert, 24, produced probably his most impressive performance in his last fight. He dominated Panama’s Jaime Arboleda (16-2, 13 KOs) on his way to an 11th-round stoppage December 12 at Mohegan Sun Arena.

Showtime’s telecast July 3 will feature a 12-round WBA lightweight elimination match between the Dominican Republic’s Michel Rivera (20-0, 13 KOs) and Spain’s Jon Fernandez (21-1, 8 KOs). The Gervonta Davis-Mario Barrios bout, Showtime Pay-Per-View’s main event Saturday night at State Farm Arena, also will be replayed as part of the July 3 broadcast.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.