Campbell joined the Magpies in the summer following his departure from the Gunners, but has had to bide his time for his first-team opportunity.
He started his first Premier League game for the club against Chelsea at the weekend and produced a solid display in the 1-1 draw.
"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 added: "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.
"He's just so experienced and he will help you make sure you make the right decisions in games.
"I think we have had a few clean sheets this season but I know we could have had a few more."