Stephan Shaw was adamant about accepting the biggest fight of his career on short notice last month.

Shaw spent entirely too much time in what he called “dark places,” depressed because his boxing career hadn’t gone as he had planned. The unbeaten heavyweight therefore felt turning down a main event ESPN will televise against Efe Ajagba on Saturday night wasn’t an option.

The St. Louis native was scheduled to face an unbeaten Italian prospect, Guido Vianello, in the 10-round co-feature before Ajagba was supposed to battle Colombian contender Oscar Rivas (28-1, 19 KOs), who withdrew due to a detached retina. But he feels boxing Ajagba will showcase Shaw (18-0, 13 KOs, 1 NC) in just the way the cerebral boxer-puncher had hoped when he and his promoter, Lou DiBella, committed to a co-promotional agreement with Bob Arum’s Top Rank Inc. last January.

“When he was offered the fight with Ajagba,” DiBella told BoxingScene.com, “I said to him, ‘Maybe you wanna stick with Guido. It’s an easy fight for you. You’re gonna look like King Kong. Maybe take that fight first.’ He was like, ‘No, man. I want the main event. I want this opportunity. I’m ready for this. I don’t wanna f--- around with Guido. I know I’m gonna beat Guido. I know I’m gonna beat [Ajagba]. Give me the main event.’ Then I made the fight for him and that was it. I made the fight for him because he wanted it.”

Shaw wants to show against Ajagba (16-1, 13 KOs) that he is ready to realize the potential he initially displayed when he was an alternate on the 2012 U.S. Olympic Team. DiBella has promoted him for the past five years, yet they have had difficulty finding prospects and later contenders to fight Shaw on his way up.

DiBella believes Shaw will demonstrate Saturday night what he has long seen in the 6-foot-4, 235-pound heavyweight.

“Stephan Shaw is the whole package,” DiBella said. “He’s promotable, he’s a good interview, he’s bright, he can fight. This is his coming-out party. I’ve always thought he was right up there in that Jared Anderson kind of discussion. But, you know, now he’s getting the opportunity to prove it.”

Arum’s company promotes plenty of heavyweights with whom it can match Shaw if he defeats the heavy-handed Ajagba in the second fight of a doubleheader ESPN will broadcast from Turning Stone Resort Casino in Verona, New York (10 p.m. ET; 7 p.m. PT). The Nigerian-born Ajagba has received more exposure, but Shaw is a slight betting favorite entering Ajagba’s second fight since Cuban contender Frank Sanchez (21-0, 14 KOs) out-boxed and out-pointed him in their 10-rounder 15 months ago at T-Mobile Arena in Las Vegas.

The 28-year-old Ajagba had surgery on both elbows before his last fight, a second-round stoppage of Hungary’s Joszef Darmos (14-6-3, 10 KOs) on August 27. The 2016 Olympian promised that he won’t follow Shaw around the ring, the way he chased Sanchez, and questioned whether Shaw will be able to withstand his power.

“It’s a tough fight,” DiBella said. “But if [Shaw] wins the way I think he’ll win, I think he’s ready for anybody. He wants the big fights. He wants the smoke. Right now, it’s very hard to get guys to accept risky fights, period. But to get a guy to rachet it up on short notice to get in a main event, you don’t see this in boxing much anymore, forget about the heavyweight division. It speaks volumes to me about the fact that this guy is the real motherf------ he thinks he is. And I respect that. I’m not gonna stand in the way of a guy like this. He want this and he got it. I applaud his attitude.”

There was no other option according to Shaw, who wants to win a heavyweight title to change the financial future for him, his wife, Kendra, their 9-year-old son, Zahmir, and their 5-year-old son, Zahke.

“It’s gonna be a very heartfelt moment for me,” Shaw said. “It’s gonna mean a lot to me because it’s going to change my life. I’m just excited, man, because I feel like this is a life-changing moment for me and I’m ready to take full advantage of it. I’m gonna be very, very happy when I beat Ajagba and move on to bigger and better things and put myself, you know, where I felt I should have been and where I need to be.”

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