Whelan admits he is sad to see Martinez leave - but wished him all the best.
Whelan said: "Roberto would start work at seven or eight o'clock in the morning and he would still be there at seven o'clock at night.
"He organises all kinds of things - he's so interested in the youngsters coming through.
"He's dedicated to players coming through at the age of 14, 15 - he wants them to play for the club he represents.
"I think he will be perfect for that. He's a wonderful guy, very honest and he gives you 150 per cent totally. We're sorry to lose him but I'm delighted he has gone to Everton.
"I wish him the very best of luck."