Levante president Quico Catalan has confirmed his club will lodge an official complaint to the Spanish Football Federation over their Copa del Rey tie with Barcelona, with reports suggesting the LaLiga champions fielded an ineligible player in the first leg.

Barca slipped to a surprise 2-1 loss in the first meeting last week, their first defeat in all competitions since a 4-3 reverse at home to Real Betis last November.

Ernesto Valverde named a much-changed line-up for that fixture, including selecting Chumi in his starting XI.

However, the Barcelona B defender was due to serve a suspension after picking up five bookings in the Segunda Division B.

The return leg was held at Camp Nou on Thursday and Catalan confirmed Levante will go the authorities and make a legal case over the matter, regardless of whether they advance or not.

"It is not an easy situation, us sporting people like to win on the pitch," Catalan said to reporters prior to kick-off.

"Whatever happens, Levante will go before the federation with this situation tomorrow (Friday).

"There will be a complaint if we do not qualify. And if we do, there will be a report to the federation to explain what has happened.

"We understand there is sufficient precedent which allows Levante to, unfortunately, go ahead to the Federation with these facts.

"Our legal department will keep working and will work all night to prepare the details of the statement we will send tomorrow. But we understand that we have the precedent and the solid foundations to do so."