Crouch struck twice in Pompey's victory over Everton on Saturday and Hart said: "I have seen Peter play since he was 16 years of age, so what he can do does not surprise me.
"I was academy manager at Nottingham Forest when Peter was coming through, so we used to play against him and I was told 'you are going to see something with this fella'.
"He was like he is now, gangly, and it takes a bit of time to get used to him, but once you see through that initial view, he knocked my head off, even at a young age.
"He was more than just a 6ft 5ins guy who could head it, he could really get hold of the ball."
Hart maintained: "I might have only had him for five games, but Peter has got more to offer than just smacking balls into the box at him.
"Peter brings people into play, he gets hold of the ball and plays at the sharp end. I have got nothing but admiration for him."