Damien Duff says "dream club" Celtic are the only side he would have left Ireland to join.
The former Chelsea, Newcastle, Fulham and Republic of Ireland winger, 39, has moved to the Scottish champions as reserve team coach.
He says coaching at Celtic is "the next best thing" to playing for the club.
"I didn't play for Celtic but to come and coach here is top class," said Duff, who has coached with Shamrock Rovers.
"I had the kits all the way through, Celtic and Manchester United were my teams. I don't think it ever got close but yeah, I would have come up here [to play].
"I have loved every minute of it. I've been here 10 days, I went through the interview process six to eight weeks ago. I've brought the family, taken the kids out of school. If anyone else came calling - not that they did - it was the only club I would have left for."
Duff, who becomes reserve team coach as Stephen McManus takes over as Under-18s coach, worked with Celtic manager Brendan Rodgers when he was a coach at Chelsea.
"He was brilliant with me down there. We would obviously talk about Celtic; it's my dream club, it was his dream club then," said Duff, who won 100 caps for the Republic of Ireland.
"I'm not claiming to know everything. I feel like I'm learning the game all over again. When you stand on the touchline it's a totally different viewpoint. I'm only a baby, I'm a year-and-a-half, two years in. So it's a massive road but I'm going to embrace it.
"Even away from the pitch, just getting into the lads' heads what it takes to be a footballer. Across the board - not at Celtic - but in England, Ireland, Scotland, lads just do enough and think just doing enough is going to get you to be a footballer but it's not.
"You've got to do more than enough every day and empty the tank. It's just that obsession.
"On the pitch I'll help them all I can. I'm on them 24/7 out there, I'm full-on, I'm passionate, I'm emotional. Once they realise it's not me just being a pain, it's because I care and I want to help."