United were far from their best in a 1-0 defeat to Mikel Arteta’s side at Old Trafford, with a Pierre-Emerick Aubameyang penalty enough to secure three points for the visitors.
Strike duo Rashford and Mason Greenwood hardly had a sniff during their time on the pitch, while Edinson Cavani struggled to make an impact off the bench as Manchester United looked limp in attack.
But it was Rashford’s performance that concerned Crooks the most and the former Spurs and United striker reminded him that he can’t take the ‘afternoon off’ when playing for such a big club.
‘United have a serious consistency problem,’ Crooks told BBC Sport.
‘Mason Greenwood was substituted and walked off the pitch looking as though Ole Gunnar Solskjaer had committed a crime.
‘Paul Pogba has so much more to give but can’t seem to find it to give.
‘And Marcus Rashford, one of my favourite players, performed as if he had been given the afternoon off.
‘Sorry Marcus, there are no days off when you play for Manchester United.’
‘Sunday’s win at Manchester United was one of the best Arsenal performances I’ve seen for some time,’ he added.
‘I criticised Mikel Arteta the last time he was in Manchester for playing a team without a recognised centre-forward. Not so at Old Trafford.
‘The Arsenal manager laid his stall out perfectly and restricted United to a handful of chances. Gabriel was at the heart of an outstanding defensive display by the Gunners.’