If Yoel Romero threw some extra mustard onto his hellacious finishing salvo that knocked out Luke Rockhold, it’s because UFC 221 was personal for the Cuban contender.

Reflecting back on the fight during a Monday appearance on The MMA Hour, Romero admitted that his third-round knockout of Rockhold was more gratifying than a usual win because of his feelings towards Rockhold. To put it bluntly, Romero is not a fan of the former UFC middleweight champion. That bad blood apparently stems from Romero’s 2016 run-in with USADA, and more specifically, certain criticisms Rockhold lobbed at Romero while “The Soldier of God” was trying to prove his innocence in a case that eventually resulted in little more than a slap on Romero’s wrist.

“You remember one day when you talked to me, I said I have only one list, a blacklist? He [was] on the blacklist,” Romero told host Ariel Helwani on The MMA Hour. “He knows why. He knows why. Because he talked a lot of (trash). After USADA, when that happened, when I had this problem with USADA, he talked (trash). Before USADA, before, every time when he saw me, whether (in) Vegas or when the UFC made something like the (athlete) retreat, he’d say, ‘Hey, what’s up, my man? You want to go out with me? I need a party.’ I’d say, okay, come on, let’s go, no problem.

“When I [was hanging out] with him, he was like a friend. He’d [put his arm around me] like this, ‘Yoel, what’s up?’ And every time, he asked me the big question. Every time, he asked me: ‘Hey Yoel, you want to fight with me?’ I’d say, ‘What?’ (He’d say,) ‘Yeah, so you want to fight?’ I’d say, ‘No, no, no. Wait, wait, wait, wait. That’s not the question. The question is, do you want to fight me?’ He’d say, ‘No, no, no. I don’t want to fight with you.’ So I’d say, ‘Okay, so you don’t want to fight me and I don’t want to fight you? That’s it.’”

Romero, 40, said he considered Rockhold a friend at that point, or at least until his dealings with USADA changed the way he looked at the pair’s relationship.

In Jan. 2016, Romero tested positive for the growth hormone ibutamoren in an out-of-competition screening conducted by the UFC’s drug-testing partner. Romero initially faced a maximum two-year suspension for the failed test, but eventually was given a truncated six-month suspension after USADA ruled that Romero’s failure was the result of a tainted supplement. The verdict meant that in the eyes of UFC and USADA officials, Romero had not knowingly taken any banned substances.

But that didn’t stop several UFC middleweights, including Rockhold, from criticizing the Olympic silver medalist — and word spread quickly to Romero.

“When I had the problem with USADA, he and Michael Bisping were the two guys, the first two guys, who were talking a lot of (trash) about me,” Romero said. “Okay, Bisping is Bisping. I don’t have a relationship, nothing (like a) relationship with this guy. But with [Rockhold]? Man, you talked like this about me? I said, okay.

“Because maybe he’s thinking, ‘Okay, this guy, 39 years old, the minimum (suspension) is two years out. (He’ll be) 41. Right? Bye bye, Yoel.’

“But God is good every time, and I’m still here. And now, that’s why when the UFC called me, I said yes about the fight.

“That’s why I said at the (UFC 221) weigh-in, when he said, ‘I am a professional,’ I said, ‘I am a professional too. I’m still here for you. I’m coming for you. Not for the belt. I stayed here for you, because this is a big opportunity — I can fight you. Everything is because you talked so bad about me. You need to pay. You need to pay.’ That’s it.”

After accepting the matchup against Rockhold on short notice, Romero missed weight by 2.7 pounds at UFC 221, meaning he was unable to compete for the event’s interim middleweight title. But that caveat ultimately mattered little, as Romero knocked out Rockhold in brutal fashion and appears to now be next in line to challenge Robert Whittaker for the 185-pound title.

And Romero let Rockhold hear about it after the fight, too.

Just seconds after knocking Rockhold out, Romero cornered his concussed foe against the fence and kissed Rockhold’s head several times. Romero said Monday that he simply wanted to offer Rockhold a message.

“In this moment, I said, ‘Hey, Luke. I love you,’” Romero explained. “‘I love you. You remember the time when you were staying with me, hanging out, and you said, ‘Do you want to fight me?’ I said, ‘You remember? And you see what happened after USADA? You remember? I’m still here. I love you.’

“He didn’t [say] anything, because he knows. He knows.”