Despite troubling Wilder in the contest, Ortiz was halted late on and says he’s studied the defeat many times since in order to iron out the kinks.
“I’ve seen the fight more than a dozen times and can tell you minute-by-minute, second-by-second what all of my mistakes were and where I went wrong.
“That fight is still a knife in my heart. I’m so disgusted with it and I want a rematch to show everyone what I would do differently.
Revealing what he would do differently, Ortiz said: “First of all, I believe that a rematch is merited, especially if Wilder doesn’t get the (Tyson Fury) fight. I’m the only fighter who has hurt Wilder and nearly had him out.
“There are a combination of things I would do differently, among them is to completely isolate myself, train harder and focus more.
“The strategy was to attack Wilder, taking it to him, which is the only way to beat a world champion, and I was doing exactly what we had planned to do to that point.
“Wilder won the fifth round, of course, but up until that point, he wasn’t doing much and we believe that we were winning the fight [The official judges’ cards had the bout even at 38-all entering the fifth.]
“That fight is still a knife in my heart. I’m so disgusted with it and I want a rematch to show everyone what I would do differently.”
Wilder is close to landing a big fish following the disappointment of Anthony Joshua deciding against a massive unification, with Tyson Fury negotiating a deal.
Talks have been ongoing for a contest in November or December on US Pay-Per-View as Wilder bids to boost his reputation against one of the best around.
For Ortiz, a crushing win over Razvan Cojanu did little more than keep him active, and should the Wilder v Fury encounter fall apart, the veteran will be on high alert for 2018.