Cristiano Ronaldo faces an improper conduct charge from UEFA before Juventus resume their bid for Champions League glory against Ajax next month.

The five-time Ballon d'Or winner scored a second-leg hat-trick as Juventus beat Atletico Madrid 3-0 to progress to the quarter-finals, overturning a 2-0 first-leg deficit in Turin.

Ronaldo celebrated the feat with a groin-thrusting celebration, apparently in response to Atleti boss Diego Simeone grabbing his crotch when his team took control of the first fixture between the teams at the Wanda Metropolitano.

Simeone was handed the same charge before being hit with a €20,000 fine, though he avoided a touchline ban.

Omnisport understands Ronaldo is similarly unlikely to receive a suspension for the first leg of Juve's showdown with Ajax in Amsterdam on April 10.

The former Real Madrid and Manchester United star will learn his fate after the UEFA Control, Ethics and Disciplinary Body meet this Thursday, March 21.

Speaking ahead of Sunday's Serie A game at Genoa, which runaway leaders Juve lost 2-0 as Ronaldo was rested, head coach Massimiliano Allegri dismissed the notion of a ban for the 34-year-old.

"Absolutely not," he said. "I think everyone celebrated their own way on the field and in the stands. I saw nothing strange, just a celebration. There won't be a ban."

Simeone also had no qualms over Ronaldo's actions immediately after the match at the Allianz Stadium.

"I'm sure Cristiano made the gesture with the same intention I did, with his people," he said.

"He will have seen how I did it at the Wanda Metropolitano and, like me, was trying to show his character."

Ronaldo's star turn against Atleti took his previously paltry Champions League goals tally this season to four, though he has scored 19 in 26 Serie A appearances.