The 24-year-old broke his left ankle and the tibia and fibula in his left leg in February after being crushed between his own car and the kerb at a petrol station after he failed to put the handbrake on, but is now ready to return.
He told the club's website: "I am filled with desire to get back playing after this long injury. I am already ready and prepared to play and this is the most important thing. I have worked and suffered a lot to be able to return for Valencia.
"I would like to thank everyone for their support during these months when one doesn't expect these things. The truth is it touched me, it was an accident."
Banega isn't the only player boss Mauricio Pellegrino can welcome back as Ricardo Costa and Jeremy Mathieu also return to the squad, but Sofiane Feghouli serves the second of his three-game ban.
Athletic captain Andoni Iraola is looking to spoil Banega's return though as he has targeted an away win to get the Basque side's season up and running.
A 1-0 win at home to Osasuna before the international break moved Athletic out of the relegation zone but they have only taken one point from three games on the road so far this season and Iraola knows that is a record which must be improved.
He told Marca: "We are coming from a good game at home, we have worked well in these two weeks and we need to we need to confirm that with a victory away from home. The Mestalla is a difficult place to go and they are thinking the same, they are in the same situation, but I see the team with confidence and with desire to win away because the numbers away from home are not good."
Jon Aurtenetxe, Inigo Perez and Fernando Amorebieta are all available again for selection after injury and suspension respectively, but Xabi Castillo has been ruled out and Carlos Gurpegi serves his one-match ban for an accumulation of yellow cards.