The €100m galactico Bale had been out since late September due to the latest of a long series of muscle problems, but sprang from the bench with half an hour to play on Tuesday at the Bernabeu and set up two crucial goals which helped Zinedine Zidane's side secure progress past the third tier outfit to the Copa's last 16.

Bale's contribution was widely praised in the local media on Wednesday morning, a change from more critical coverage during recent months over form and repetitive injury.

But later in the day there were further concerns as the 28-year-old did not take part in training with Zidane's squad. And reports emerged claiming the club's plan had always been to ease him gradually back into action due to his past injury record, hence the chance he may not make Saturday's game at San Mames.

A club statement after training confirmed Bale's absence, while fellow winger Lucas Vazquez has returned from a minor knock picked up in last weekend's 3-2 La Liga win over Malaga.

"The squad completed the second session of the week at Real Madrid City and began preparing for the league match against Athletic, which will be played this Saturday at San Mames (8:45pm CET)," the statement said. "Lucas Vazquez, who on Monday trained inside the facilities, worked with the group. The players who started against Fuenlabrada trained at lower intensity. Luca and Asensio continue with their recovery processes, while Bale worked inside the facilities."