Celta Vigo coach Paco Herrera is concerned his side's Copa del Rey triumph over Almeria will have a detrimental effect on their chances against Levante in their Primera Division clash at Estadio de Balaidos.
Celta needed extra time to beat the Segunda Division club 3-2 on Thursday to set up a fifth-round tie with Real Madrid, and Herrera fears the cup game may have taken a lot out of his players.
``Extra time was not wanted because the league is very important,'' Herrera said ahead of the meeting with sixth-placed Levante.
``We are happy because we have moved to the next round. (The match against) Real Madrid is the gift we wanted to give our fans.
``I have to be worried about the tiredness of the players heading into Sunday. We've made a huge effort against a great team.''
Celta head into the weekend 14th in the table, just three points above the drop zone, but Thursday's victory coupled with an impressive 1-0 win at Real Zaragoza last weekend will give Herrera's side confidence.
They continue to be without Samuel Llorca, whose knee injury has kept him out of the squad all season. He is likely to be out for some time yet after undergoing surgery.
Juan Ignacio Martinez's Levante will be without Dariusz Dudka (hernia) as they bid for their seventh win in La Liga this term.
A comfortable 4-1 Copa del Rey victory over Segunda Division side Melilla may have given them a much-needed confidence boost after they were thrashed 4-0 by Barcelona last weekend.