Roy Nelson expected to fight Quinton Jackson at Bellator 200. “Rampage” apparently wasn’t into it, though, and much to his surprise, that’s when Bellator called with Mirko Cro Cop’s name.

Nelson (22-15 MMA, 1-1 BMMA) admits Cro Cop (36-11-2 MMA, 0-0 BMMA) simply wasn’t on his radar. The Croatian heavyweight never has fought for Bellator and has been executing his craft in Japan in recent years while flirting with the idea of retirement.

Nelson happily accepted the offer, though. He already owns a third-round TKO of Cro Cop from UFC 137 in October 2011, and Nelson said there was no reluctance in running it back.

“Cro Cop was actually a surprise,” Nelson told MMAjunkie. “I was supposed to fight ‘Rampage,’ but he didn’t want to fight so they went out and got Cro Cop. I’m all about rematches. I’ve been trying to get them through my fighting career, but I’m all about it. It’s the one thing I always wish I had, so I want to give someone else a chance.”

Bellator 200 takes place May 25 at The SSE Arena in London. The card airs via same-day delay on Paramount.

As soon as the matchup between Nelson and Cro Cop was announced, some concerns began to surface. At the tail end of his UFC run in 2015, Cro Cop admitted use of a banned substance around the time of a drug test administered by the U.S. Anti-Doping Agency. He was handed a two-year suspension, which Cro Cop essentially ignored by going to Japan and fighting under the Rizin FF banner.

At 43, Cro Cop has been in strong form. His eight-fight winning streak dating back to August 2014 is the longest of his MMA career, and although the results coincide largely with fighting in unregulated territory, Nelson did acknowledge that Cro Cop still has lots of skill, even if he’s getting some outside help.

“I think Cro Cop’s definitely always improving with age, but I think he’s back on the special supplements, better supplements than usual,” Nelson said. “Throughout my whole fight career, the only reason people want to fight me or have a chance to beat me, is if they get something. It’s something I just know that everybody is just on it. It’s one of those things where it’s an uphill battle. If you can help prevent it, cool. But at the end of the day I just go out there and fight whoever they want me to fight.”

Nelson said he’s not going to make any special requests in terms of additional drug testing for Bellator 200, but he hopes there’s more done than his previous bout. Bellator 200 will be overseen by Mike Mazzulli, president of both the Association of Boxing Commissions and the Mohegan Tribe Department of Athletic Regulation, who was also in charge of Nelson’s most recent contest, a majority-decision loss to Matt Mitrione last month at Bellator 194.

“My last fight we got tested I think three or four weeks into camp,” Nelson said. “I wasn’t even licensed by Mike and then we didn’t get tested fight night. Someone could have technically got back on a cycle or something stupid. I don’t know. If you’re going to drug test, drug test.”

Regardless of whether Cro Cop is clean at this stage of his career is not something Nelson is going to obsess over. “Big Country” has been outspoken against the use of banned substances in the past, but he said it’s an obstacle he’s capable of overcoming to get the win.

Moreover, Nelson said the most important thing was to get another fight quickly after his loss to Mitrione, no matter the opponent. The defeat knocked Nelson out of the Bellator World Heavyweight Grand Prix, and his goal is to find a way back into the tournament.

Bellator has not officially labeled Nelson vs. Cro Cop as an alternate matchup. However, Nelson said if he can get a big win over Cro Cop at Bellator 200, he can’t imagine a situation in which he wouldn’t get the call if a replacement fighter was needed.

“You’ve got to take the positive with the negative,” Nelson said. “This is an opportunity to get back in the tournament. I’m trying to be an alternate or something like that. And you only get paid when you fight, so the more fights I have, the better.

“I just want to go out there and get a W. I also want to get some revenge for my good friend (Muhammed) Lawal; that’s about it. I just want to get back in the tournament and hopefully fight Matt again.”

For more on Bellator 200, check out the MMA Rumors section of the site.