The former England goalkeeper believes the current Three Lions first choice can achieve as much as his Spanish counterpart, and he can be a key figure for years to come
Martyn, who played 23 times for England, believes there are parallels to be drawn between Hart’s club career at Manchester City and that of Casillas at Real Madrid.
He told talkSPORT: “He reminds me of Casillas. He got into the team at Real Madrid very early and you can see the career he has had.
“Hopefully Joe can emulate that because he’s doing fantastically well.
“As long as you steer clear of the injuries, don’t do anything silly and stay at one of the top clubs then it all bodes well for his international future.
“It’s up to the even younger lads to try and oust him and that will make him better as well.”
Hart has made 22 appearances for England and has conceded just 14 goals, keeping a clean sheet in the Three Lions’ 5-0 victory over Moldova in their first World Cup 2014 qualifier.