Article 15 of UEFA's regulations states that bans of more than one game are for offences such as abusive language towards a match official, serious assault or for receiving a caution or red card on goal.
"In case of serious offences, the UEFA Control, Ethics and Disciplinary Body is entitled to augment this punishment, including by extending it to other competitions".
And according to former Premier League referee Mark Clattenburg, Ronaldo was correct.
If this happens Juve bosses are expected to lodge an immediate appeal, meaning Ronaldo could still face United.More news: Australian tourist haven suffers twin shark attacks
AFP Sport understands, however, that an extension to the one-match ban is unlikely.
Juventus' Portuguese forward Cristiano Ronaldo (L) cries next to Juventus' Italian midfielder Federico Bernardeschi after receiving a red card during the UEFA Champions League group H football match between Valencia CF and Juventus FC at the Mestalla stadium in Valencia on September 19, 2018. Most of the viewers felt that it was a harsh decision and didn't warrant even a yellow card.
Cristiano Ronaldo should escape an increase on his one-match ban in the Champions League but Juventus' star summer signing might not get off so easily in the race for the Ballon d'Or.
"There was a small push from Ronaldo which resulted in the Valencia defender falling to the floor but that was not violent conduct".More news: Moon, Kim visit 'sacred' Mount Paektu
"It was spotted by the additional assistant, standing behind the goal, who may have thought Ronaldo threw an elbow but that was not the case".
Ronaldo was clearly frustrated when Murillo fell to the ground, running his hand over the top of his opponent's head before gesturing for him to get up.
"As far as I could see, it was a pretty normal clash".More news: Passengers suffer nose, ear bleeds on Jet Airways flight