The January transfer window is now open, meaning clubs in England and Scotland are able to buy and sell players again.
Several deals have already been lined up - including Cody Gakpo's switch from PSV to Liverpool and David Fofana's arrival at Chelsea from Molde.
Celtic have also been busy in preparation for today - with Tomoki Iwata, Alistair Johnson and Yuki Kobayashi all moving to the Scottish Premiership leaders.
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