A close companion of Los Blancos' playmaker has lashed out at Santiago Solari.

Real Madrid manager Santiago Solari has received fresh criticisms for his supposed 'unfair treatment' of midfield star Isco. A close friend of the ex-Malaga midfielder Aitor Costa has labeled the former Castilla boss as a "murder of football" in a rant on Instagram following Los Blancos' win against Real Betis on Sunday.

For the umpteenth time this season, Isco was denied a spot in the starting XI as Real Madrid took its chances against the Beticos despite missing a host of its key players to injuries. While the likes of Gareth Bale, Toni Kroos, Marco Asensio, Lucas Vazquez, among others were all unavailable for the league encounter, Solari overlooked the Spanish midfielder and resorted to utilizing the club's youth.

Vinicius Jr, Fede Valverde, Cristo Gonzalez, Dani Ceballos, and new signing Brahim Diaz were all involved in the game while Isco looked on from the bench. With the clash almost ending in a 1-1 draw, it took the dead ball expertise of former Betis star Ceballos to snatch all the three points for Real Madrid via a free-kick very late into the proceeding.

Having been quizzed as to why he denied Isco the opportunity to feature against Betis despite Real Madrid's struggles, Solari insisted that there was not any personal sentiment attached to the player's omission.

"We played a serious game, we are who we are and we are all the team," Solari said.

"It is made up of those who play and those who do not play.

"In no way is there anything personal.

"The squad is what it is and we all do our best, I as a coach, and everyone can play, they are all part of the squad."

However, a friend of Isco, Aitor Costa, has called out the Real Madrid head coach over his consistent refusal to play the midfielder in matches.

"Solari has the same idea of football as I do of engineering," his post on his Instagram story read.

He then went ahead to describe the Merengues' boss as a "murderer of football".

Despite Real Madrid insisting that the Isco is not for sale earlier this month, the latest development indicates that the club may finally have to arrive at a compromise and allow the Spaniard to leave.