LAS VEGAS – None of the first four Devin Haney fights Eddie Hearn has promoted have made him nervous.

The British promoter admits, though, that Jorge Linares is a true threat to Haney’s reign as a WBC lightweight champion. Linares is 35 and has lost by technical knockout five times, but the Venezuelan veteran is an intelligent, skillful, strong former champion who, on paper, appears to be the most formidable foe of Haney’s five-year pro career.

“I’m so excited about Saturday because I have to be honest, every fight we’ve been in with Devin, I haven’t been that concerned,” Hearn said during a press conference Thursday at Mandalay Bay. “I’m concerned, which is great news because it means we’ve got a real fight.”

The 22-year-old Haney (25-0, 15 KOs) is heavily favored ahead of their 12-round fight Saturday night, 12-1 according to most Internet sports books. Linares nevertheless is a more imposing opponent than the three boxers Haney has beaten in his 135-pound title fights – Russia’s Zaur Abdullaev (13-1, 8 KOs), the Dominican Republic’s Alfredo Santiago (13-2, 5 KOs) and Cuba’s Yuriorkis Gamboa (30-4, 18 KOs).

Haney has repeatedly called out elite lightweights, but Linares (47-5, 29 KOs) is the closest the Oakland native and his team have come to securing a top opponent.

“It’s been frustrating for all of us, trying to find that fighter to step up,” Hearn said. “You know, whether it was Lomachenko, who [Haney was] chasing through the WBC, you know, that slipped away. There was talks of Ryan Garcia and Teofimo Lopez, and people may not realize, but [Haney was] ready to take those fights a long time ago. And that comes from the build of Devin Haney, [his father] taking him to Mexico as a young fighter, learning the trade. People talk about the experience of Jorge Linares. But people are probably underestimating the experience of Devin Haney as well.”

Linares, a Tokyo resident, made his pro debut when Haney was 4 years old. The former WBA/WBC lightweight champion was dropped three times and stopped in the first round of his 140-pound debut by Mexico’s Pablo Cesar Cano two years ago, but Hearn envisions a competitive fight Saturday night at Mandalay Bay’s Michelob Ultra Arena (DAZN; 8 p.m. EDT; 5 p.m. PDT).

“Jorge Linares is a tremendous fighter,” Hearn said. “Great footwork, great hand speed, great intelligence as well. This is a really good matchup. … This is a really, really good fight.”

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