The skillful, strong Cuban knocked out durable Spanish contender Sergio Garcia in the third round on the Terence Crawford-Errol Spence Jr. undercard in July 2023. Tellez remains the only opponent to stop Garcia inside the distance.

A one-sided points victory over former unified 154-pound champ Julian Williams on the Gervonta Davis-Lamont Roach undercard a year ago further strengthened Tellez’s standing in his division, because he won the WBA’s interim championship that night.

A legitimate title shot seemed well within reach for a formidable fighter who handled much more experienced opponents without much difficulty and typically took advantage of undercard spots on high-profile Premier Boxing Champions cards. Tellez was consequently around a 7-1 favorite to defeat Germany’s Abass Baraou on August 23 at Caribe Royale Orlando, where Tellez’s handlers at Boxlab Promotions regularly stages shows.

An unfazed Baraou out-worked Tellez in his adopted backyard, dropped him in the 12th round and beat him unanimously on the cards (117-110, 116-111, 115-113). One of boxing’s most promising young fighters suddenly found himself in rebuilding mode.

“I was going through some personal issues,” Tellez told The Ring regarding training camp before he faced Baraou. “Fundamentally, it was about discipline. I thought that those things that were happening outside the ring wouldn’t affect me. I was wrong. Everything wound up going against me in the sense that it led to the loss. I wasn’t a hundred percent focused, and that’s the bottom line.”

Tellez declined to elaborate on the troubles he endured while preparing for the Baraou bout.

He preferred to focus on his opportunity Saturday night to start regaining the momentum he lost seven months ago. Tellez (11-1, 8 KOs) will battle Brian Mendoza (23-4, 17 KOs), another former interim 154-pound champion eager to reclaim his standing in their division, in the co-feature on the Sebastian Fundora-Keith Thurman undercard.

“Mendoza is someone that’s among the elite,” Tellez said, “someone that’s really strong, has earned his respect in the division and someone that has had a really good pro career. I’m sure that it’s gonna be a good fight on [Saturday night].”

Mendoza viciously knocked out Fundora in the seventh round of their April 2023 bout in Carson, California. The Albuquerque, New Mexico native lost unanimous decisions to former WBO champ Tim Tszyu and onetime WBC interim champ Serhii Bohachuk in his two subsequent bouts.

Tellez, 25, and Mendoza, 32, know winning Saturday night would at least put one of them in position to call out the Fundora-Thurman winner. Fundora (23-1-1, 15 KOs), of Coachella, California, is scheduled to defend his WBC junior middleweight title against Thurman (31-1, 23 KOs, 1 NC), of Clearwater, Florida, in the main event of PBC’s Prime Video pay-per-view show at MGM Grand Garden Arena (8 p.m. ET; 5 p.m. PDT; $74.99).

“My mentality is regaining what was lost [against Baraou],” Tellez said. “But I know that if I train the way that I am and stay focused, that I’m gonna be able to regain what I had and more, because I’m doing the right things.”

While he didn’t prepare properly for the Baraou bout, Tellez, a 3-1 favorite to defeat Mendoza, according to DraftKings, denied that he simply underestimated the then-unknown underdog. Xander Zayas (23-0, 13 KOs), the WBA/WBO 154-pound champ, told The Ring before he beat Baraou (17-2, 9 KOs) by split decision January 31 in San Juan, Puerto Rico, that he sensed Tellez overlooked his former sparring partner.

“I don’t underestimate anybody,” Tellez said. “He has two feet, two hands, just like me. And I never overlook anybody that’s in front of me. But like I’ve said, the whole thing was that my mentality wasn’t stable. I didn’t have my head in the game the way that I needed to, and that was my downfall in the end. But I wasn’t about to overlook someone that was in front of me, much less somebody like that.”