Instead, Gastelum will meet Brian Melancon (7-2 MMA, 1-0 UFC) when the UFC touches down at Bankers Life Fieldhouse in Indianapolis. It won't be the same level of name as a Thiago would bring to the table. But Gastelum will simply focus in on getting another win under his belt, and his first after dropping from middleweight to welterweight.
"The opponent change, I was kind of bummed that (Thiago) had to pull out of the fight," Gastelum told MMAjunkie.com Radio (www.mmajunkie.com/radio
). "He's a guy I respect very much, and I wanted to test myself. He's a veteran and has been in there with a lot of big-profile names like Josh Koscheck and Mike Swick. At the same time, I thought it was a fight I could win. But things happen, and people get injured, and this time it just happened to me. But I'm excited to be fighting again."
Gastelum wasn't supposed to win "The Ultimate Fighter" when he upset heavy favorite Uriah Hall in April. For that matter, he wasn't supposed to win any of his fights in the "TUF" house, either. But he did, anyway, upset after upset to get to the finals against Hall, who had sent two "TUF 17" fighters to the hospital with knockouts.
He knows what it's like to be the constant underdog and overcome the odds. This time, he's favored over Melancon, who in July returned to the cage after nearly two years away and pulled off an upset himself, knocking out Seth Baczynski with one second left in the first round at UFC 162.
But despite having very few people thinking he could beat Hall, Gastelum believed in himself.
"I felt the energy, and the crowd really had my back," he said. "I even heard my name shouted during the fight. That was something I didn't expect, but I thought it was cool at the same time. I came into that fight real confident and I had a lot of people behind me that believed in me. That's what's most important in a training camp – you have to have people around you that believe in you, and that's what I had."
The "TUF" title and UFC contract allowed him to quit his job as a bail bondsman to focus on fighting full-time. And with that came the decision to drop from middleweight to welterweight. That meant enlisting the help of famed MMA nutrition consultant Mike Dolce.
Gastelum admitted he cheated a couple times while on Dolce's diet. But the decision to go with him is one he's glad he made, and he plans to stick with it rather than having a big post-fight weight gain just to have to drop back to 170 again later.
"I feel fantastic – my weight's dropped, and I feel faster and stronger," Gastelum said. "You're going to see a whole different Kelvin Gastelum than you're used to. The hardest part was getting used to the meals. i'm used to eating whatever I want, and this is the first time I've had to follow a strict diet. I sneaked in a couple treats for myself every now and then, but overall I stuck to it pretty good. My weight's on track right now, and I'm going to be ready to go on Wednesday.
"After the fight, I'm going to stick to it. I don't want to get too heavy and have to cut all this weight again. I'm going to stay lean and mean in case (UFC matchmaker) Joe Silva calls and says to get ready in a couple weeks. That could very well happen, and I want to stay ready."
That stronger and faster Gastelum might be trouble for Melancon if the Californian has his way. In his first fight at welterweight, which will be part of UFC Fight Night 27's main card on FOX Sports 1 from Bankers Life Fieldhouse in Indianapolis, Gastelum has a statement in mind.
That way, even though it won't come against a bigger name like Thiago, the division at least will be put on notice that there just might be a legit prospect in the mix.
"Every fight I go in trying to knock the guy out or submit him," Gastelum said. "The Uriah Hall fight was the only fight of my career to go to a decision. Going down to 170, I want to make a statement and really put on a show and put Melancon down, whether it be a knockout or submission."