Martin O'Neill has been speaking to the media before Celtic visit St Johnstone in the Premiership on Wednesday (20:00 BST). Striker Kasper Hogh has been back in training the past couple of days and fellow injury absentee Kieran Tierney returned to work with the squad this morning. Both are in contention for the game, with Hogh the likelier, while there are "a couple of other fitness issues for players".