Former Germany stopper Jens Lehmann has suggested that Joe Hart did not work hard enough to develop into a world-class goalkeeper.
Hart is currently regarded as England's number one, despite finding himself out on loan at Torino after falling down the pecking order at Manchester City.
Lehmann - who won the Premier League with Arsenal in 2004 - insists that he used to be impressed by Hart, but that he has failed to build upon a promising start to his career.
The 47-year-old told The Sun: "England have always had good players, but what they are still missing is a world-class keeper.
"I saw Joe Hart play some great games, but I saw mistakes as well. When I saw him after a couple of years, he was still making the same mistakes. His education stopped and he did not work on his weaknesses."
Hart is expected to be named in England's starting lineup when they face Germany in Dortmund on Wednesday night.
