Ezequiel Garay has extraordinarily hit out at Valencia for sacking Marcelino three matches into the new LaLiga season.
Marcelino departed on Wednesday despite leading the club to successive top-four finishes in the past two campaigns.
He also won the Copa del Rey with the club last term - beating Barcelona in the final - but following a reported falling out with owner Peter Lim he has been replaced by Albert Celades.
Garay, who started all three LaLiga games this season under Marcelino, made his feelings clear with an explosive social media post.
"After many years with you (not only in Valencia) I know perfect how you are, both professionally and personally," he wrote on Instagram.
"But not only I see it, you have shown it to everyone. Because the road is demonstrated by walking and you have made a clean, transparent and healthy route. You go through the big door mister.
"Whoever took this decision not only trampled over you, but over a whole squad and fanbase.
"I say it loud and clear: IT'S NOT FAIR."
Dani Parejo, Valencia's captain, also appeared unimpressed with the club's call to replace Marcelino.
"Mister, I wish you the best," Parejo wrote on Twitter alongside a photograph of him embracing the coach.
"I'm sure you'll be fine wherever you go. Thank you for making the club bigger and me a better player."