Johnny Walker is wasting no time.

The Brazilian light heavyweight prospect quickly became a fan favorite in the UFC after knocking out Khalil Rountree and Justin Ledet in a combined time of two minutes and 12 seconds. Days after his recent win, Walker went on social media to call for a top 15 opponent.

Cirkunov was matched-up against Ovince Saint Preux at UFC 235, which takes place Saturday in Las Vegas, but was left without an opponent on Feb. 9. Walker wasted no time, offering to replace “OSP” against Cirkunov, and got the fight 48 hours later.

The Brazilian did his camp for his UFC Buenos Aires debut training in England, and then moved to Thailand to prepare for UFC Fortaleza. This time, since he was enjoying some family time in Rio das Ostras after the 15-second win, Walker split his short camp training at Paulo Rambinho in Rio das Ostras, Fabio Noguchi in Curitiba, and then Capital da Luta in Sao Paulo.

Walker is an odds-on favorite despite only having a couple of appearances in the Octagon, while Cirkunov, officially ranked No. 14 in the UFC’s light heavyweight division, holds stoppage wins over the likes Nikita Krylov, Ion Cutelaba, Alex Nicholson, and most recently Patrick Cummins.

Asked if the Latvian talent will be too much of a step up in competition so early in his UFC run, Walker disagrees.

“If I fight someone lower in the ranking last my last two fights, the result would be the same as my last two fights,” Walker recently told MMA Fighting. “If I don’t fight someone good, that can hang in there with me, the fight will last 15 seconds again. I wish I could fight three rounds, and I think Misha can give me that.”

What if he beats Cirkunov in seconds, though?

“I don’t know, man,” Walker said with a smile. “I would be happy. Bring the next.”

“A fight is unpredictable,” he added. “I just want to win. I don’t know how it’s going to be, but my hands have to be raised in the end.”

A lightning-fast win over someone like Cirkunov, who has only lost to Glover Teixeira and Volkan Oezdemir over his last 11 bouts, would boost his stock. With fellow Brazilian light heavyweight Thiago Santos campaigning to be next for the winner of Jon Jones vs. Anthony Smith, can Walker jump the line?

“I don’t want to jump the line, man,” said Walker, predicting that Jones “will beat (Smith) up” and remain champion on Saturday night. “I want everything to happen on the right time, on God’s time. Let it happen naturally.”

Whether Walker will get to the top of the division and challenge for the 205-pound belt, that remains to be seen. However, the talented Brazilian doesn’t think anyone will dethrone Jones “until I get there.”

“He’s waiting (for me),” Walker said. “I think I can give him a fight. I know that.”