Nico is suffering from "an injury to the adductor muscle in his right thigh" and Inaki from "non-specific pain in the sole of his left foot", Athletic Club said on Saturday about the Williams brothers' fitness.

Both had to withdraw before the end of Friday's La Liga game against RCD Mallorca at San Mames due to these setbacks.

Nico and Inaki "are awaiting further developments" to see if coach Ernesto Valverde can count on them for Wednesday's first leg of the Copa del Rey semi-final against Atletico Madrid at the Civitas Metropolitano. The younger Williams is the one who has it more complicated, reported 'COPE'.

However, after the game, Valverde was confident that "it's nothing" about Inaki and did not rule out Nico for the Copa del Rey clash.