Melvin Guillard won't exactly have the clearest head in his return to the pro MMA world this weekend ... 'cause later this month, he's due in court in his domestic violence case.
The former UFC fighter was arrested in Colorado way back in April 2018 after cops say he violently attacked his mistress after she allegedly asked when he was going to leave his wife.
Cops say the 36-year-old choked the woman repeatedly ... and said the victim was "scared he 'might kill her.'"
Guillard's case in the Colorado court system hasn't progressed quickly ever since he pleaded not guilty to the crime .