By Ewan Murray Arsenal’s trip to Atalanta in their opening Champions League game of the season promised goals. So, naturally it was a tame goalless draw. There was not a great deal of goal-mouth action in either half as defences reigned supreme for much of the encounter, but David Raya was ultimately Arsenal’s hero as he denied Mateo Retegui from the penalty spot after half-time. While not a disastrous result for the Gunners – and arguably a half-decent one given Atalanta’s European pedigree – Mikel Arteta will have been left a little frustrated by his side’s lack of cutting edge in the opposi…