The Newcastle United full-back sees Campbell as a "legendary figure".
Simpson told the Evening Chronicle: "When I was a boy I watched his whole career unfold for Tottenham, Arsenal and England in the World Cups and European Championships.
"It's just an honour to be alongside him on the pitch and in training.
"You can only learn from him and gain good advice.
"On the pitch he's always communicating and making sure things are running smoothly."
Simpson went on: "Everybody knows the type of experience Sol has.
"He has that presence and he's always there. He's a big lad and he talks to everybody, passing on his advice.
"He was playing 20 years ago, so you know you have to listen to him because he's been there and done it."