Blackwell revealed he has had lots of interest from several clubs in England U-21 keeper Scott Carson, who is second choice behind Neil Sullivan.
Blackwell said: "Scott is only just turned 19 and is keeping 'Sully' on his toes. He is a Trojan in training and gets so passionate about the game that he even gets upset if he makes a mistake in the warm-up. The coaches feel he will be a fixture in the England Under-21 side for the next couple of years.
"It's just unfortunate I can't play him in our first team at the moment because 'Sully' has so much experience and is playing so well."