Tom Boyd believes Celtic's Champions League play-off collapse against LASK last month is the cause of their recent poor form. Martin O'Neill's side threw away a four-goal aggregate lead in Austria as they missed out on Europe's premier club competition. Celtic were knocked out of the Premier Sports Cup and beaten in the league by rivals Rangers, either side of losing their Europa League opener 3-1 against Hungarian outfit Ferencvaros, making it three defeats in their past three matches.