"I still have a lot of friends there at the club, not just the players but the manager, staff and higher up," said the Republic of Ireland international.
"I made a lot of friends in my time there and it will be strange playing against the blue and whites.
"I'll still be doing my job, trying to get the winner and hopefully get West Brom the three points. It's about business as usual. I won't celebrate out of respect if I do score."