But Benitez said: "I have been very clear. The player had said before that he wanted to play Champions League football. We knew that and so tried to sign a good player. It is that simple.
"If your captain wants to leave, it is a problem, but that's football."
The Spaniard's latest comments are bound to further anger O'Neill, who was furious last week at the manner of Liverpool's approach for the England midfielder.