Athletic Bilbao coach Ernesto Valverde admits there's frustration over losing Inaki Williams.

The striker is leaving Athletic this week to join Ghana's Africa Cup of Nations squad.

Valverde said: "Iñaki is an important player for us and he is also in great form, but we must accept that he will not be with us this month. You have to push forward in the same way that you did when other players were missing and we performed at a good level.

"We have a deep squad. The players coming in are responding and the young kids are taking a step forward. Iñaki's loss must be resolved together. A season is not completed by 11 players.

"It is essential that these younger players enter the first team little by little. It is necessary to combine that they gradually enter and at the same time sustain the results. They have to be able to withstand pressure and at the same time make all their qualities seen. They have to write the future."