Coppell said: "We have found the Irish players to have a really good mentality. It's almost as if they have something to prove on a week-by-week basis.
"Stephen Hunt came over to Palace when he was 15 and 12 years later he's still got that ‘I've got something to prove' mentality. That goes an awful long way in any profession.
"Longy (Shane Long) is totally off the cuff. He has not had a formal footballing education and was still playing hurling at 15 or 16. He does things in an unconventional manner and that is his attraction.
"Kevin Doyle has learnt his trade with us in the past couple of years. This season has been hard for him but he just keeps bouncing back.
"At 24 or whatever he is, he is the senior partner in that combination but because they are Irish I think they complement each other well."