Curbishley worked with Young at Charlton Athletic.
"I think Martin (O'Neill) just fancies Carlos Cuellar more than he does Luke," Curbishley told the Sunday Mercury.
"If Martin agrees to let Luke go then someone will definitely take him. He can play right-back, he can play left-back, he's great on the training ground so someone will sign him.
"He turned his back on England, he's got his own opinions on that, but he was being considered for that. I think he was looked at strongly because of his versatility.
"But he needs to get back playing, he's one that needs to be playing every week.
"He's one of those sorts of people who doesn't like missing games so I can imagine that it's been quite frustrating for him."