Darren Bent insisted he had to leave Aston Villa after too many "slaps in the face".
Brighton defender Greg Halford has agreed to extend his loan deal from Nottingham Forest until the New Year.
Tom Rogic insists he does not regret his move to Celtic, despite returning to Australia on loan with Melbourne Victory.
The midfielder has joined Victory, who are managed by former Rangers defender Kevin Muscat, until the end of the season after failing to establish himself as a first-team regular at Celtic Park.
The 21-year-old has made just five starts, along with nine substitute appearances, since joining from Central Coast Mariners a year ago.
Rogic admitted the decision to leave Celtic temporarily was not difficult, but added: "Don't get me wrong, I'm happy there, it's a fantastic club, but I think it's important for me at this stage in my career to be playing.
"It's a fantastic squad there and it's very difficult to break into. There's a lot of great players.
"It's been a good learning experience. I feel I'm a much better player than I was 12 months ago so I look back on the past 12 months as a positive.
"It's great set-up with amazing fans and it's great to be a part of that. I enjoyed winning the double last year.
"It's a successful club, in the European Champions League, so I certainly don't have any regrets."
Rogic has eight caps for Australia and admits he had to move to boost his prospects of adding to them at the World Cup, where the Socceroos face Spain, Holland and Chile in the group stage.
"It's certainly a big factor," he said. "I don't think there's any Australian footballer right now that wouldn't want to be a part of that World Cup.
"At 21, the thought of possibly being at a World Cup in Brazil is pretty special.
"Obviously I want to do everything I can to be part of that."