#3 United lacked a right-sided midfielder
This has been United’s shortcoming throughout the season so far. Anthony Martial has been one of the better players for them, as he prefers to cut in from the left wing. He also scored his 9th goal of the season yesterday.
However, they have lacked a similar attacking threat on their right-flank. Lingard has been tried as a right-winger, but he is more comfortable playing as a central midfielder. Rashford too has played on the right wing at times, but prefers to be the centre-forward.
United started the match with a 4-2-3-1 formation, with Rashford as the lone striker, and Lingard and Martial as the wide midfielders, but their formation kept changing to a 4-4-2 whenever they had possession, as Martial started to move inside and partner Rashford in the attack.
Lingard dropped to the midfield, but could not make those vital forays through the right flank. As a result, United were dependent on right-back, Ashley Young, to attack via their right flank. Solskjaer could think of signing a genuine right-sided midfielder like Marco Asensio or Gareth Bale to solve this problem.