Villa boss O'Neill defends selling Cahill to Bolton
"The injury was very unfortunate for Curtis (Davies), but that's why we took on another centre-half (Zat Knight). That was primarily because I never thought Martin would play that many games.
"He's played a full season which is remarkable, and we also had Olof Mellberg. I wasn't pushing Gary out the door, but I understand him wanting to play, especially as he was down the pecking order."