United best hope is to win the Europa League as they face Celta Vigo in the second leg of the semifinal at Old Trafford on Thursday holding a 1-0 lead; surely Mourinho’s interest in the rest of the domestic season will be limited.
The United manager’s thoughts were clearly on the Europa League based on Sunday’s teamsheet. He made eight changes from the side that beat Celta and he set his team up to stifle Arsenal while looking for Anthony Martial on the break.
It worked in a tight first half but nine minutes into the second half, Arsenal got a slice of luck that separated the sides.
United were having their best spell of possession at the beginning of the second half when Arsenal broke the deadlock in the most unlikely manner.
Xhaka, for so long seen as the symbol of Wenger’s poor judgement and the failure of Arsenal’s transfer policy, took a speculative shot from 30 yards.
It looked the sort of effort that David De Gea would scoop up with ease until the ball hit Ander Herrera on the back and looped into the net.
No goalkeeper could have done anything about it.
Mourinho will be unhappy with Herrera, who turned away from the shot and ducked, for his part in the goal.
Within three minutes, Arsenal had doubled the lead. Alex Oxlade-Chamberlain sent in a looping cross that Chris Smalling seemingly thought he could clear but the United defender jumped under the ball instead.
Behind him, lurking, was Welbeck, who headed it expertly in off the bar.
United’s long unbeaten run was over.
Mourinho brought on Jesse Lingard and Marcus Rashford for Henrikh Mkhitaryan and Herrera but United were unable to trouble Arsenal and Wenger finally got his first league win over nemesis Mourinho.