Initially Askren was openly critical of the UFC's decision to give Punk (AKA Phil Brooks) a contract, taking to Twitter to denounce the decision.
However, Punk has since started training alongside Askren at the Roufusport gym and the former wrestling champion has come to respect him.
Askren told MMA Fighting: "I was just talking sh*t on Twitter.
It's what I do. He's been outstanding in the gym. He's been in there every day. It's not like he came in here and said, 'I'm a superstar, I'm going to get preferential treatment.' He just acts like one of the guys, just working out. It's outstanding.
"Some people who come from high levels in other backgrounds where they're used to being the best or used to being on a kind of pedestal, it's hard to kind of lower yourself again and just be one of the grunts.
"I kind of enjoyed that challenge in MMA. When I walked into any wrestling room, I was like the guy and then when I switched to MMA, then I'm just another guy and I don't have a lot of skills. He's probably even more so than me, because he was huge in WWE."
He concluded: "This is a physical sport where you fight people every day in the gym. It's been awesome to see how he's just come in and worked hard and isn't really worried about anything else."