This Saturday’s middleweight bout between Kelvin Gastelum and Nate Marquardt will be Gastelum’s first bout at the 185 limit since winning the 17th season of The Ultimate Fighter in 2013.

According to Gastelum (pictured above, right), it’s going to be his last.

“I think the difference between middleweight and welterweight is, I can be a mediocre middleweight or I can be the welterweight champion,” Gastelum said (as quoted by Dave Doyle at MMA Fighting) at UFC 188 open workouts in Mexico City today. “I want to be the welterweight champion. I plan on going back, and I plan on getting back in the boss’ good graces after this Saturday.”

The latter is particularly significant for the Arizona native, whose MMA record stands officially at 11-1 (excluding his four wins at TUF). Gastelum missed weight in two of his last three bouts, prompting UFC President Dana White to demand he move up to middleweight.

In his last appearance in the Octagon, at UFC 183 against Tyron Woodley, Gastelum missed weight by nine pounds. He went on to suffer the only loss of his career in what he now calls, in an interview with E. Spencer Kyte on the UFC website, an anomaly:

“I have a lot of bottled up emotions from my last fight and I’m going to let it all out in this next fight,” Gastelum said. “I’m not happy at all with my last performance – it was a s***ty weekend, a s***ty situation. It was a bad day on the job. We’ve all had those and I plan on making up for it on June 13.”