Real Madrid midfielder Fede Valverde allegedly punched Villarreal's Alex Baena in the car park following Los Blancos' 3-2 defeat to the Yellow Submarine in LaLiga on Saturday.
According to reports in Spain, Valverde sought out Baena after the match at the Santiago Bernabeu and hit the winger in the face.
Marca say they spoke to the Uruguay international and he confirmed the aggression, claiming Baena had made insults relating to the problems during his partner's pregnancy (the couple had been close to losing their baby) in the teams' Copa del Rey match in January and again on Saturday.
On Instagram, Baena denied those claims and said he was 'sad' about the incident.
"Very happy with the impressive victory of the team at a stage like the Santiago Bernabeu, but at the same time very sad about the aggression I suffered after the match and surprised by what is being said about my person," he wrote.
"It is totally false that I said that!"
Madrid twice led in the game on Saturday, but Villarreal took all three points thanks to a late winner by Samuel Chukwueze at the Bernabeu.
Los Blancos will find themselves 15 points behind leaders Barcelona in LaLiga if the Catalans beat Girona at Camp Nou on Monday, although their focus is now very much on the Champions League quarter-finals and the Copa del Rey final next month.
Real advanced to the Copa final after thrashing Barcelona 4-0 at Camp Nou in the second leg of the teams' semi-final last week. They face Chelsea in the last eight of the Champions League at the Bernabeu on Wednesday night.
Meanwhile, Villarreal say they have footage of the incident involving Valverde and Baena, with the Madrid midfielder potentially set for a ban. However, it is unclear what punishment the Uruguayan could face at this point.
