Within the last hour, Valencia has fired Paco Ayesteran. He had been given (allegedly) two more matches to prove himself, but he’s been pushed out sooner. Ayesteran arrived in February 2016 as part of Gary Neville’s staff and replaced him in March.
Voro Gonzalez is replacing Paco for now, but there is a lot of speculation that Marcelino Garcia Toral will be the permanent hire. There is some question as to whether he can legally do so, though. The Spanish Federation rules state that a coach cannot coach another team in the same division in the same season—the question is what does “season” mean? This article says the RFEF considers it to start in July when coaches and players are registered, but whether that is the interpretation that is going to be followed, who knows.
As far as is known Marcelino has not been in touch with Valencia, though there are rumors the club has contacted his agent.