The Frenchman was brought to England by City before moving onto the Owls.
Helan told City's website: "Dedryck Boyata is the only one of my age group who is still at City, really. I'm looking forward to catching up with him and hoping that he will feature in the game.
"We keep in touch but maybe not as much as we should. It's harder when you're both at different clubs and I live in Sheffield now - it was taking me 90 minutes to travel from Manchester at the beginning so I had to move.
"I'm not a City player anymore and I don't feel I have anything to prove to anyone. City are a huge club and need big established stars in their team to compete with the best."