The 34-year-old confirmed on Monday that he would be quitting the sport this summer, bringing an end to a successful 17-year career.
Wilkinson, who currently plays his rugby in France with Toulon, is best known for playing a key part in England's World Cup win in 2003.
"He is one of the biggest ever legends to play rugby," Haskell told BBC Sport. "He was the David Beckham, he put rugby on the map, he won the World Cup for England.
"The best thing about Jonny was he was single minded and focused, but he was very much a team man. He gave up time to help me and if he decided to go into coaching, that is where his expertise would help."
Wilkinson is expected to feature for Toulon on Saturday when they defend their Heineken Cup crown against Saracens in Cardiff.