"Gabby did great last season and there would have been concerns about second-season syndrome - not a bit of it,'' said O'Neill.
"Gabby was absolutely brilliant. Really great and I am delighted for him.
"He is a player, I think we would all agree, who has improved beyond all recognition in 16 or 18 months. And he is improving, and he is trying to get better.
"And I will tell you what I like about him - he is trying to get hold of the ball, trying to get his body in the way. He is prepared to get kicked. He is a professional footballer."