Pep Guardiola has been slammed as "disgusting" for his treatment of Manchester City goalkeeper Joe Hart by the club's former player Joey Barton.
England goalkeeper Hart has been dropped from the starting line-up for both of the former Barcelona and Bayern Munich head coach's first matches in charge.
Willy Caballero has started against Sunderland and Steaua Bucharest, while reports in England and Spain suggest City are closing in on the signing of Barca goalkeeper Claudio Bravo as Guardiola eyes a shot stopper possessing better skills with his feet.
Barton - now of Rangers - feels there is no justifiable explanation for how Guardiola has treated Hart, who has spent 10 years with City but is now edging closer to the exit door.
"It is not the club I left," Barton, who departed City in 2007, told talkSPORT.
"The club I left and watch now are two totally different organisations. The club I played for wouldn't have treated a player that had been a servant for as long as Joe has in the manner that it has. It is disgusting.
"It is common human decency, regardless of how good a coach you are. Why treat him like that?
"He is a full international, somebody who, probably before City took the money, could have gone on to bigger and better things himself but stayed and wanted to be at City.
"I don't see what he has done wrong to be treated the way he has. His attitude isn't terrible. I don't like this.
"I've watched Caballero and are you telling me Caballero is better with his feet than Joe Hart? I haven't seen it.
"Why not let him fight for his place and then if he is not good enough say: 'I have given him an opportunity'. That's what every manager should do, give everyone an opportunity."
Hart, 29, has been linked with loan moves to Everton and Sevilla.