We spoke with the Raw commentator about LaVar's wrestling debut ... and Otunga says it was the most entertaining part of the night, even if he went "off the rails."

Otunga hopes Ball gets invited back ... saying he'd dust off his spandex for a shot at LaVar ... if Vince gave him the green light.

Otunga -- who's engaged to Jennifer Hudson -- also talked to us about a movie he made with his son for Father's Day ... and it's safe to say David Jr. takes after his star parents.