Athletic Bilbao face an uphill task in their attempt to reach the Copa del Rey Last 16 stage having lost the first leg 1-0, but their excellent home form should give los Leones reason for optimism.

Meanwhile, Celta Vigo should be more concerned with their league position, although the Sky Blues do have a very good result ahead of the match at New San Mames.

Not too many people expected Athletic to shine this season having been largely disappointing last term, but the arrival of Ernesto Valverde changed everything.

Los Leones in turn enjoyed a bright start to the league campaign and climbed to fourth place following some impressive results.

The home win over mighty Barcelona proved Athletic are serious top 4 contenders, with away draw against Sevilla another step in the right direction.

However, despite the team vying for Champions League positions in the league, they will certainly want to do well in the competition that has brought them so much pleasure in the past.

Having won Copa del Rey on no less than 22 occasions, Athletic Bilbao are rightly considered 1.75 (3/4) favourites to overturn a one-goal deficit against Celta and make it to the next stage.

Mikel San Jose is doubtful with an ankle injury he picked up in training, but Kike Sola will not be in contention despite resuming full training following a three-month spell on the sidelines.

Aymeric Laporte is battling a leg problem, whereas Unai Albizua is unlikely to return despite making progress after a hamstring injury.

Probable starting line-up (4-2-3-1): Iago – Iraola, Gurpegui, San Jose, Balenziaga – M. Rico, Iturraspe – Susaeta, Herrera, Muniain – Aduriz.

Having escaped the drop on the final day of last season, Celta Vigo have shown some improvement this term, but the team remain involved in the difficult relegation tussle.

The Sky Blues seriously improved their survival chances with unexpected away wins over Malaga and Sevilla, but they slipped back to the danger zone having lost three of last four matches in the league.

Home win over Almeria was followed by Copa del Rey triumph over Athletic Bilbao, but the 3-0 setback at Real Valladolid acted as another blow to the players’ confidence.

And with important home game against Osasuna next in the league, boss Luis Enrique cannot really afford to field his strongest side at the New San Mames.

Boss Luis Enrique has no fresh injury worries ahead of the trip to Bilbao, but Samuel Llorca remain on the sidelines.

Probable starting line-up (4-2-3-1): Alvarez – Mallo, Cabral, Costas, Castro – Alex Lopez, Rafinha – Orellana, Nolito, Krohn-Dehli – Santi Mina.