Fresh off filming “The Ultimate Fighter,” it appears Julianna Pena’s rivalry with Amanda Nunes is heating up.

Peña (11-4 MMA, 7-2 UFC) scored a shocking upset finish to dethrone longtime bantamweight champion Nunes (21-5 MMA, 14-2 UFC) at UFC 269 this past December. The pair have been matched up for a rematch later this year.

Before they lock horns for a second time, Peña and Nunes just spent eight weeks together coaching Season 30 of “The Ultimate Fighter.” And though Nunes still holds the featherweight strap, Peña took a shot at the validity of her title.

“Let’s talk about this for a second,” Peña told “The Schmo.” “So Holly (Holm) and Germaine (de Randamie) both said that they’re not going back to featherweight at 145 and they’re going to stay true bantamweights at 135. Megan Anderson retired. Felicia Spencer retired. Can you name anybody else in the division other than Amanda? She’s a champ in the ’45 division of who? She says that she’s still, you know, the champ of a division of one person. So that’s nice.”

Season 18 “Ultimate Fighter” winner Peña didn’t give out too much when asked how the filming of the show went, but did say she noticed a change in Nunes’ behavior.

“I would say that she’s a little bit more high-maintenance than I had originally anticipated, that’s for sure,” Peña said.

“I would definitely say that there’s a little bit of a sad bravado about her that I think she’s really wanting to come back and get her belt back. So we had some words, we had some choice words. You’re going to have to watch the show.”