Former Manchester United goalkeeping coach Eric Steele believes that Manchester City's Joe Hart has slumped because he has nobody challenging him for his place in the first team.
The England international has come under criticism once again following a blunder which led to Fernando Torres's winning goal against City at Stamford Bridge on Sunday.
Following his performance, calls have been made for manager Manuel Pellegrini to drop the 26-year-old from the starting lineup.
"Has he been challenged enough at club and international level? I don't think he has," Steele wrote in The Telegraph. "Joe challenges himself more than anyone but he's not had the required challenge at City since Shay Given left.
"You need somebody breathing down your neck and putting you under pressure in training every day. It's the same at international level too, it's only now that the next generation are now coming through."
Meanwhile, City are preparing to take on Newcastle United in the Capital One Cup this evening.
