However, Chelsea defender Cahill believes that Hart is one of the best keepers in world football.
"For me he's one of the best there is. I've trained with him for a long time now, I've seen him up close and personal and he's top drawer," he told reporters.
"That's the way football is. You're not always going to keep clean sheets every single week. As defenders and goalkeepers there is always going to be a stage in your career you might make a mistake or two. But I think we'll see in the character, the way that he can bounce back and others can bounce back, that's the most important thing."
Hart has represented the Three Lions on 33 occasions.