Barcelona could be thrown out of the Copa del Rey for fielding suspended defender Chumi Brandariz (pictured) in their last-16 first leg defeat after opponents Levante said they would lodge a complaint with the Spanish Football Federation.
Levante president Quico Catalan said his club, which won the first leg 2-1, says the youth player was ineligible.
Barca won the second leg 3-0 to go through but Catalan says Levante will go forward with the complaint regardless.
Barcelona, a four-time defending Copa champion, has denied any wrongdoing.
It says it is backed by a rule that allowed Chumi to play.
Levante says Chumi should not have played because of an accumulation of yellow cards with Barcelona’s “B″ team, arguing that his suspension applied to the senior team as well, including in Copa del Rey matches.
Real Madrid were eliminated in the round of 16 of the Copa in 2015 for using striker Denis Cheryshev while he was suspended.
The biggest stumbling block to any complaint is that the deadline expired on Monday though the RFEF has previously approved claims made by teams after a deadline has passed.
Barcelona spokesman Josep Vives said the club believed Chumi, 19, was eligible to play.
“We’ve analysed the situation and concluded that playing Chumi in the Copa del Rey was within the rules. The federation have also told us nothing.”