Real Madrid could be thrown out of the Copa del Rey in the wake of reports that Denis Cheryshev was not eligible to play in their last 32 fixture against Cadiz.
Cheryshev was on loan at Villarreal last season, and picked up three bookings during his side's 2014/15 Copa del Rey campaign, which should have resulted in an automatic one-match ban tbat would have seen the Russian sit out Wednesday's fixture, a match which Madrid won 3-1.
Instead, the 24-year-old was named in the starting line-up and opened the scoring in just the third minute.
News regarding Cheryshev's alleged ineligibility soon circulated around the Ramon de Carranza, with Cadiz fans chanting the winger's name, while urging Real boss Rafael Benitez to check Twitter.
Speaking after the match, Cadiz president Manolo Vizcaino confirmed that the club will make a formal appeal.
"The circumstances require a quick decision," Vizcaino told reporters. "The board has decided to make the complaint about the illegal lineup including the player Cheryshev. We have decided to do it, with pain in our heart, as Madrid as a club are our friend. But a firm and unanimous decision has been taken."
Cheryshev was substituted shortly after half-time, and Benitez has revealed that this was due to the speculation swirling regarding his eligibility.
"Clearly, the club did not know anything, the federation had not said anything, neither had Villarreal, so we thought we could field him," Benitez said. "As soon as we were aware, after half-time, we substituted him immediately to show good faith."
It would seem unlikely that Real will emerge from the situation unscathed, even though the los Blancos hierarchy insist they were not aware of the issue.
Osasuna were kicked out of the competition in September after fielding Unai Garcia in a 2-1 victory win over Mirandes. Garcia should have been suspended after he was sent off against Alaves last season.