Melvin Guillard says he and Michael Johnson always had a "weird" relationship.
The two UFC lightweights (and former teammates) will square off Saturday, in the co-main event of UFC Fight Night 37 at O2 Arena in London.
Officially, it's the first meeting between the two -- although according to Guillard (31-12-2), he and Johnson (14-8) used to go full speed at practice all the time while they were teammates at the Blackzilians camp in Boca Raton, Fla., in 2012.
"When we would spar, it would get serious," Guillard told ESPN.com. "Enough where they would have to split us up. We couldn't even spar with each other after awhile. It was a serious battle in the room. We were literally fighting each other."
Guillard blames the cold relationship on the general atmosphere he felt while at the Blackzilians. A veteran of the UFC since 2005, Guillard joined the team in 2012 and says he instantly felt a rivalry between himself and Johnson.
"There was never any incident to be honest," Guillard said. “When I first started with the Blackzilians, Mike was there before me. The first thing I heard was, 'Which one of y'all is going to be the top 155-pounder?'
"They put that in our heads. One of us had to be the alpha male. Me being who I am, I'm always going to be the alpha male. I don’t care. It started off rocky."
Looking at the two fighters' careers, much has changed since their first acquaintance.
When Guillard became a Blackzilian, he was on a 5-1 run and was considered a potential title contender. Johnson was 1-2 in the UFC.
Today, Johnson is considered one of the brightest talents of the weight class, coming off wins over Joe Lauzon and Gleison Tibau. Guillard, meanwhile, appeared to be on his way out of the UFC last year, before he rebounded from a 1-4 skid.
Guillard recognizes the progress his former teammate has made, but doesn't believe it will be enough. He still remembers Johnson as a kid trying to play catch-up.
"Michael is improving tremendously," Guillard said. "If I had fought him two or three years ago, I'd smash him in the first round. Easy. Now? I can't say I'm going to knock him out in the first round like I would have. He's a smart fighter.
"There is no bad blood, but I've been in this game too long to let some rookie come in and beat me and think he's better than me. That's kind of how I felt when I trained with that team."
At 30 years old, Guillard still has time in the sport, but is aware many have given up on him in terms of a potential titleholder. Acknowledging as much irritates him, as he believes that even if he never wins a title, fans should respect him more.
"All they say is, 'He's going to win big or he's going to lose big and get choked out,'" Guillard said. "I hate some of those comments. 'Melvin will always be a gatekeeper.'
"People don't realize how hard it is not only to fight in the UFC but stay in the UFC. I've been in the UFC for nine years straight. I haven't been cut or kicked to another promotion and I'm proud of that."
That said, Guillard still believes a UFC belt is in his future. Should he defeat Johnson on Saturday, Guillard plans to call for a top-five opponent and then a title shot.
"Will I get a title shot? Yes. Will I be champion? Yes," Guillard said. "I haven't given up on myself.
"[UFC champion] Anthony Pettis is a good fighter, but I feel like I'm bigger, stronger and faster. I can beat anybody in my weight class. I have to go make a statement against Michael Johnson and then I see myself fighting for the title within two fights."