Former NFL all-pro Greg Hardy knows he has to prove to many people that he has overcome his troubles outside the Octagon. Hardy was released from his NFL contract for allegations, and now he's looking to make an impact in the UFC's heavyweight division.

Former title contender Derrick Lewis has had some choice words for Hardy ever since he was signed to the UFC. Now, as Hardy prepares to face Alexander Volkov on Saturday at UFC Fight Night 163, he is responding.

"I think he's a like a felon," Hardy said in an interview with RT Sport. "He's been to prison. I just don't think somebody that's been to prison is allowed to say what the standard is. We don't listen to people that contradict themselves."

Lewis spent over three years in jail for a parole violation in 2005 after being charged with aggravated assault. Lewis had allegedly beaten a Ku Klux Klan member while still in high school.

While Lewis has stated that MMA helped him overcome his struggles, he has been outspoken against Hardy denying any wrongdoing in his domestic violence charges. Hardy had the conviction overturned and removed from his record after the victim declined to appear in court.