3 things Arsenal got wrong in 2-1 defeat to Manchester United

#1 Arsenal couldn't deal with the intensity in the last 20 minutes

Plan B worked for United

In the last 20 minutes, United were playing much better football following the introduction of Marouane Fellaini, Anthony Martial and Marcus Rashford. The Arsenal fullbacks who had grown weary by then couldn't effectively deal with the pace of Martial and Rashford as they regularly had the beating of Arsenal's defenders.

Martial was particularly menacing and he should have got an assist after playing a delightful cross to Marouane Fellaini at the far post. The Belgian headed it on to the post but the ball bounced back into goal off of Rashford. However, the goal was ruled out as Rashford was a yard offside.

Fellaini almost always looked like a threat and he had the height advantage which he once again used to great effect to head home the winner in the 92nd minute of the game. Manchester United once again grabbed a late goal to get all 3 points and have now confirmed a berth in the next year's UEFA Champions League.

Meanwhile, Arsenal will hope that their decision to rest their top players will be justified when they visit the Wanda Metropolitano to take on Atletico Madrid in the all-important second leg of the UEFA Europa League semifinal.