Celtic defender Cameron Carter-Vickers admits he is still "a work in progress" after returning to action following almost nine months out with an Achilles injury. The USA international made his comeback in Monday's season-opening 1-0 victory against Dundee and while delighted to be back on the pitch, he says there's improvements to come from himself and the team. Martin O'Neill's side are two weeks away from their crucial Champions League play-off against Austrians LASK and have opted to postpone their Premiership game at St Johnstone that was due to be played between the two legs.