Barcelona earned a spot in the quarterfinals of the Copa del Rey on Thursday, but its continued participation in the tournament is still under threat.
Lionel Messi and Ousmane Dembele led Barcelona to a comfortable 3-0 win over Levante at Camp Nou Stadium, helping it advance 4-2 on aggregate. However, the Catalan club could be disqualified for allegedly using a suspended player in the first leg.
Levante said it will make a formal complaint to the Spanish soccer federation on Friday, ahead of the draw for the quarterfinals.
The four-time defending Copa champion has denied any wrongdoing for using youth player Juan "Chumi" Brandariz in last week's match in Valencia.
Levante said 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 matches.
The Spanish federation is expected to rule on Levante's complaint before Friday's draw.
Real Madrid was eliminated in the tournament's round of 16 in 2015 for using striker Denis Cheryshev while he was suspended.
With Messi back in the lineup after being rested in the first leg, Barcelona easily reversed the 2-1 deficit from the first match. The Argentine playmaker set up goals by Ousmane Dembele in the 30th and 31st minutes, then sealed the victory by scoring in the 54th.
Barcelona has made it at least to the quarterfinals in the Copa in nine straight seasons. It won the title five times in the last seven years.
Earlier Thursday, Espanyol defeated Villarreal 3-1 at home with two goals by striker Borja Iglesias to advance 5-3 on aggregate, while Real Betis salvaged a 2-2 draw at Real Sociedad to reach the last eight on away goals after a 0-0 first-leg draw.
Real Madrid, Girona, Valencia, Getafe and Sevilla also made it to the quarterfinals.