Celtic are in an exciting frame of mind with their Champions League clash against Borussia Dortmund on the immediate horizon and have started the campaign in excellent form. Brendan Rodgers is enjoying his side’s synchronicity on the pitch, which has led to the Bhoys going on a nine-match winning run across all competitions. However, their test away to Dortmund at Signal Iduna Park will be a major step up from their usual level of opposition. Nuri Sahin’s men were Champions League finalists last season and brought in the likes of Serhou Guirassy and Yan Couto during the summer window. Frustrat…