Real Madrid's Dani Carvajal will not face a Uefa charge after denying biting Atletico Madrid's Mario Mandzukic.
Replays of an incident in the second half of Tuesday's Champions League quarter-final show defender Carvajal's mouth close to Mandzukic's arm.
But Carvajal and striker Mandzukic have both said that there was no bite.
The 23-year-old Real right-back also appeared to swing an arm at the Croat in an ill-tempered game, but will not face any charges.
Uefa, however, has said it has opened proceedings against Atletico for a pitch invasion.
After the goalless draw, Carvajal told Spanish media: "I want to make it clear that I have not bitten anyone."
And striker Mandzukic, 28, backed up that assertion by tweeting: "Yesterday's game was very tough and the two teams gave everything.
"But for me there is no controversy, no bite, no nothing."
Despite both players' assertions, Atletico captain Gabi had called on Europe's governing body to respond.
"I can't judge the incident but if Uefa study the images and see something they should take action," he said.
"They are unpleasant incidents and if the footage is so clear then perhaps the disciplinary committee should step in."
Mandzukic had already suffered a cut to the head earlier in the game when he was caught by Sergio Ramos's elbow.