A tearful Ronaldo left the pitch in disbelief but Allegri maintains he would have avoided a red card if UEFA had opted to approve the use of VAR for Europe's premier club tournament.
Meanwhile, TUKO.co.kepreviously had reported that Ronaldo's elder sister Katia Aveiro has lashed out at German referee Felix Brych after issuing a straight red card to the Portuguese.
Max Allegri's team will face the Red Devils at Old Trafford on October 23.
AFP Sport understands, however, that an extension to the one-match ban is unlikely.
UEFA's Control, Ethics and Disciplinary body will meet on Sep.
"I just heard he said it was because of hair pulling".
It was the 11th red card of Ronaldo's career, while his first in the Champions league and has ruled out the former Real Madrid footballer in their next match against Swiss side Young Boys at home. We can't go back in time because Ronaldo has already been sent off and the match has finished'.
The five-time Champions League victor has been the top-scorer in the Champions League the past six seasons.
Juventus are yet to confirm whether or not they will be appealing the red card. Juventus were awarded with two penalties which they converted on, even though they played much of the game with 10 men due to Ronaldo being sent off.