Kelvin Gastelum has informed the UFC he wants to fight in May, and he wants there to be a guaranteed title shot on the line.

Gastelum (14-3) is coming off a first-round knockout over Michael Bisping in November. The UFC was interested in booking him again as early as this month, but the 26-year-old said he needed time off after a busy 2017.

The ideal time frame for his return is May, and Gastelum says he's looking for a No. 1 contender fight -- middleweight or welterweight.

"Just the fight that will get me to the title shot," Gastelum told ESPN's Five Rounds podcast. "That's the fight I want. I know I probably won't get a title shot next, but I want to fight the No. 1 contender.

"If it's at welterweight, I will make the cut. The cut is dreadful and the diet is extreme, but if it's worth it, I will do it."

Gastelum has bounced between those two weight classes in his career, but the UFC has been far more keen on him as a middleweight.

He is officially 2-1 in his past three fights at 185 pounds, and believes the top opponent for him to guarantee a title shot against is Ronaldo 'Jacare' Souza (25-5), who is coming off a first-round stoppage over Derek Brunson last month.

The UFC has a pay-per-view event on May 12 in Rio de Janeiro, which would seem like an obvious landing spot for that potential bout. Gastelum has previously said he would never fight in Brazil, due to differences with the commission there, but may change his mind.

"I would love to fight in Rio, and obviously a fight with Jacare would propel me to where I want to go," Gastelum said. "I'm scared of that commission. I don't know what to think of the commission.

"I should probably talk to someone in the commission or [UFC vice president of regulatory affairs] Marc Ratner. Hopefully, he'd keep me safe and nothing happens to my [drug] samples. I just don't know what to think of the commission over there."

Jacare Souza knocked out Derek Brunson in January, and seems primed for a middleweight title shot soon. Streeter Lecka/Getty Images

Of course, those discussions will only come up if the UFC expresses interest in the proposed fight, which Gastelum believes it should.

In a perfect world, Gastelum would love to challenge current middleweight champion Robert Whittaker now, while he says they are both entering their respective primes -- but he understands the next middleweight title shot is likely going to highly ranked Yoel Romero.

In the meantime, he wants the fight that will establish him as next in line.

"Two young dogs going at it for the strap would be nice," Gastelum said. "We haven't hit our prime yet, and the rest of the guys are on their way out. I still feel like I'm in the beginning stages of my career.

"But I'm obviously not mad if Yoel takes the fight. He just beat the No. 1 contender, which was Luke [Rockhold]."