Manchester United are often considered by many to be the pinnacle of club football and it is seen when many players who leave have to take a step down. Building back themselves to reach those levels again is a challenge and for some, it never happens. It looks like it won’t be a challenge for one particular player who left the club this summer and is already thriving in new surroundings. Mason Greenwood has so far scored in every appearance for Olympique Marseille and he continued that streak on his competitive debut as well. Mason Greenwood ‘exceptional’ on debutOlympique Marseille kicked off…