Baines is the subject of an offer from Manchester United this week and Whelan says Baines was always destined for the top.
"Bainsey was a wonderful player for us and he has gone on to the next level with Everton and England.
"It is great to see and a testimony to Wigan Athletic.
"'He was a key figure in this club's success and is one of the best around.
"There is so much to his all round game but we at Wigan always knew that.
"It was great to see him break into the England set up - he is a world-class left back."