Freddie Roach believes Jose Aldo needs to polish some of his boxing moves before he can reclaim the UFC featherweight title from Conor McGregor.

During a recent interview with FightHub's Marcos Villegas via Bloody Elbow, the esteemed boxing trainer chimed in his thoughts on Aldo's first round loss to McGregor in December 2015.

He commended McGregor's knockout stance since the Irishman had his feet planted firmly on the ground while moving backwards to evade Aldo's initial jab.

Roach revealed one cardinal rule in boxing: never move backwards in a straight line. He said the move only works when an opponent is moving towards you. McGregor was perceptive and lucky enough to take advantage of Aldo's mistake.

The 55-year old American trainer added that McGregor was already set to throw a punch when Aldo moved forward to approach him. The Irishman's steady footing and the Brazilian's apparent lack of patience resulted in a devastating one-punch knockout, which you can view right here.

Roach scoffed at the sequence and said it was "a very common shot in boxing." He said moving forward to meet a punch headfirst is a mistake he never wants his boxing pupils to make.

The 2012 Nevada Boxing Hall of Fame inductee concluded by saying MMA fighters have an unpolished standup game, and that the Dec. 12 title bout between Aldo and McGregor proved his point completely.

In all fairness to Aldo, his forward-moving punch did hit McGregor right in the right eye. Both fighters landed crushing left hooks simultaneously, but it was McGregor who had the better stance.

Aldo voiced his opinion on the knockout last week. He said if it was the other way around, and if it was his punch that had landed completely, it would have been him who would have won the fight in convincing fashion, Pundit Arena reported.

"My punch barely hit but it cut him," claimed the dethroned UFC featherweight champion. "Imagine if it connected completely, it would have ripped his head off. But he had the merit to connect a good punch and end the fight."

Aldo took a one-month hiatus after the McGregor knockout. He soon got back to the publicity game on Jan. 27, when he posted a picture of him on Instagram, stating he is ready to step inside the octagon again.

The 29-year old Manaus native had one condition: he would only return to the UFC if his next fight would be against McGregor, per MMA Fighting.