"I think what he did for the combat sport, he made it what it is today," Guyer said. "He paved the way for the great boxers, even the UFC, where that is today. So he's one-of-a-kind, the way he went about things.
"People can say that he's cocky and stuff. But he was just very confident in himself. It was fun to watch him."
Guyer said he's watched a lot of Ali highlights.
"It's really incredible, all he did," Guyer said. "It's a sad day for the whole world. Especially the combat world, if you're into that stuff. Like I said, he's the greatest of all time. It's a sad day."
When asked about Ali, Chris Archer allowed that, "It's hard to say, because everything I saw from Muhammad Ali was a recording or hearsay.
"But he was definitely a person who stood up for what he believed in," Archer said. "And that's admirable. And he was somebody who had a lot of conviction behind his actions in his craft. And that's something as an athlete, or anybody in the world, can learn from, is to have conviction behind their craft."
Evan Longoria pointed out that Ali had suffered from Parkinson's for so long that his death probably brought "a bittersweet moment for a lot of people."
"He's at peace now, obviously," Longoria said. "But we lost a legend in sports.
"And one of the greatest, if not the greatest competitor of all time. So it's a sad day. I'm not a boxing fan. I like watching it, but I don't really follow it. But it's not hard to know that he was the greatest."
Longoria noted that he could not speak to all of Ali's accomplishments.
"I just read that he received the medal of freedom," Longoria said. "He had his title rescinded, because he wasn't going to fight because of his religious beliefs. He definitely transcends sport in general. It's a sad day for all of the sporting world."