Michael Stewart has now raised his doubts about whether Celtic will bring in a sufficient number of players during the January transfer window. Only days remain before the window slams shut and Brendan Rodgers has only seen one name come through the door. Nicolas Kuhn signed from Rapid Vienna and he made his Celtic debut during the 1-0 win over Ross County on Saturday. Whether it be this month or in the summer, Michael Stewart made it clear that if and when Celtic bring in new players, they have to be ‘starting XI’ signings, as he told The Scottish Football Product. There is no doubt that ther…