MADRID, March 28 — Athletic Bilbao have been one of the surprises of the La Liga season so far, with brilliant displays from brothers Inaki and Nico Williams helping to spur a top-four challenge under the calm guidance of former Barcelona manager Ernesto Valverde.

Unbeaten at home since early August, the Basque club sit fourth in the table and will play in their 40th Copa del Rey final on April 6.

But before travelling to Seville to face Mallorca in their third Cup final in the last five years, when they will bid to end a 40-year major trophy drought, Athletic take on La Liga leaders Real Madrid in the Spanish capital on Sunday.

Coach Valverde will have to decide whether to rotate his team with the Cup final around the corner, or whether to go all-out against Real in an attempt to fire up his side after a two-week hiatus due to the international break.

He could opt to be cautious with Nico Williams, Oihan Sancet, Dani Vivian and Unai Simon all coming back from international duty with Spain, with veterans Yuri Berchiche, Ander Herrera and Oscar de Marcos returning from long injury layoffs.

After consecutive league wins on the back of holding second-placed Barcelona to a draw and knocking out Diego Simeone’s Atletico Madrid in the Copa del Rey semi-final, a statement victory at Real would give Athletic a huge confidence boost and keep them on course for a spot in the Champions League next year.

Athletic have 56 points, one point ahead of fifth-placed Atletico, who travel to Villarreal on Monday.

Girona, who will host seventh-placed Betis on Sunday, are third on 62 points but have recently struggled and won two of their last seven matches.

If Athletic want to continue their winning run, they will have to do what no side has done this season — beat Real Madrid at the Santiago Bernabeu.

Undefeated at home, Carlo Ancelotti’s side have been held to only three draws at the Bernabeu in all competitions so far this campaign.

Real’s only two losses this season came at the hands of local rivals Atletico, a 3-1 La Liga defeat in September and a Cup exit on penalties in mid-January, both at a raucous Metropolitano stadium.

Yet Real will be missing Brazil winger Vinicius Jr, who is suspended after receiving a fifth yellow card in their 4-2 win at Osasuna before the international break.

Vinicius has hit a rich vein of form, scoring six goals in their last four games in all competitions. Real are comfortably top of the La Liga standings on 72 points, eight ahead second-placed Barcelona, who will host Las Palmas on Saturday. — Reuters