Real Madrid's woes deepened on Thursday after Cadiz confirmed they have filed a formal appeal against the Spanish giants for fielding an ineligible player in their Copa del Rey clash.
The two sides met in the first leg of their last-32 tie at the Ramon de Carranza on Wednesday evening, but news circulated midway through the first half that Denis Cheryshev should not be on the pitch due to a suspension.
The Russian winger opened the scoring after just three minutes, but he was supposed to serve a one-match ban as he collected three yellow cards while he was on loan at Villarreal last season.
Real manager Rafael Benitez substituted the player after only 40 seconds in the second half and said management wasn't aware of the ban.
"Clearly, the club did not know anything, the federation had not said anything, neither had Villarreal, so we thought we could field him," he said. "As soon as we were aware, after half-time, we substituted him immediately to show good faith."
However, Cadiz have decided to take the matter further and have lodged a complaint to the Spanish Football Federation (RFEF) over Cheryshev's inclusion.
"The RFEF has accepted our appeal and time has been given to Real Madrid to present a defense they deem relevant," a Cadiz statement said.
They [RFEF] has also sought different reports which confirm that such an infraction existed.
"Cadiz will again show their respect for Real Madrid and their fans and will not make any type of comment until there is an official statement from the Committee of Competition with an edict about the magnitude of what has happened."
If found guilty, then the 19-time Copa del Rey winners could be thrown out of the tournament. Osasuna were kicked out earlier this year after they were found guilty of fielding an ineligible player.
The RFEF is expected to announce a decision as early as Friday.