Manchester United veteran Jonny Evans has called time on his international career.
While O’Neill is disappointed to lose out on Evans’ services, he could only praise the center half.
"He's a top player, top individual to have in any squad, any team," said O'Neill.
"The fact that Manchester United still value him as they do is a testament to that as well."
"It's disappointing but it's not something we haven't discussed," added O'Neill.
"We've discussed it over the last six months every time we've caught up. He never really wanted to make that decision but I think he realized to give himself a chance of making a real impact at Manchester United, it meant that the international breaks would probably help physically.
"He has a lot of commitments, three young kids as well. International football, when you've been doing it for 18 years, it's a big commitment. But in terms of what he's brought, what he's given us over the years, he has been fantastic, a top-class player and top-class individual as well."