Ronaldo, 33, was sent off in his first Champions League game for Juve since his club-record move from Real Madrid in the off-season.
It also marked his first ever red card in the competition after just 29 minutes into his first return to Spain - following an altercation with defender Jeison Murillo.
He will miss Juve's next Champions League match at home to Young Boys, but it also in danger of missing an emotional reunion with former club Manchester United if the ban is extended.
And Marcelino said that his dismay was clear to see.
"He was very upset, even crying, because he said he didn't do anything wrong," he said in his post-match press conference.
"I haven't seen the play which ended up in the red card."
Despite the red card, Juventus went on to win the match 2-0 thanks to a pair of penalties from Miralem Pjanic.
"It's obvious that the penalties have impacted us," the Valencia coach continued.
"The penalty just before half-time was a real blow, we then had to try and pull ourselves together.
"The other penalty was then a death sentence for us, conceding two goals to such an excellent team makes the task wholly difficult."