Real Madrid boss Santiago Solari questioned Isco's professionalism in response to a recent tweet from the Spain international.
Isco has struggled for regular action since Solari replaced Julen Lopetegui as head coach earlier this season.
The attacker recently claimed that he 'does not receive the same opportunities' as his teammates, which has led to a defiant response from the Los Blancos boss.
Indeed, Solari has suggested that Isco's training performances have not been at the level required to be considered for a regular spot in the XI this term.
"A professional footballer's job is to work and to train at 100% to be of service to the team," Solari told reporters. "The team is good and the players are all working well so that the team is the priority."
"Football is about work and talent. You have to give everything in training and to be available when you have to play."
Isco has scored once and provided just one assist in 15 La Liga appearances for Madrid this season.