Celtic are now well into the transfer window and will be keen to keep hold of their star players between now and the end of the month. Nicolas Kuhn has been the only confirmed arrival at Parkhead in what has been a quiet few weeks in Glasgow’s east end; however, there is still time for movement to happen in both directions. Brendan Rodgers will also be desperate to retain his key men in the hunt for the Scottish Premiership title. Nevertheless, the Irishman isn’t naive and will know the unpredictable reality of the market from his experiences as a manager. Liel Abada and Cameron Carter-Vickers…