St Johnstone are very much up against it with the visit of Celtic in the Scottish Premiership on Saturday. Not only are they facing the reigning champions, who are on a hot streak of eight consecutive victories, but they do so without a permanent manager in place. Craig Levein was sacked by the Perth side earlier this month, and despite heavy links to former Celtic captain Scott Brown and Aberdeen assistant Peter Leven, they haven’t yet secured a replacement. Coach Andy Kirk will be in the dugout opposite Brendan Rodgers, and while the home side have trust in their temporary leader, they are u…