#3 Angel Di Maria
Angel Di Maria was one of the most anticipated and high-profile Manchester United signings in the post-Ferguson era.
The Red Devils signed the Argentine international on a then-British transfer record £67.5 million in 2014. There were huge expectations from Di Maria, and he was handed the iconic No. 7 shirt. However, like most of the No. 7s in the post-Ferguson era, Di Maria could never adjust to the rigours and demands of English football.
The Argentine superstar enjoyed a flying start to life in England, but could not capitalise on his good form. Di Maria was also the victim of a burglary attempt during his first year in Manchester, making it even more difficult for him to adapt to life in Manchester. He was visibly shaken after the incident, and became a shadow of the player he once was at Real Madrid.
The now-33-year old would only last a solitary season at Manchester United, registering 32 appearances in his first and only season in English football. Di Maria was directly involved in 16 goals (four goals, 12 assists) during his Manchester United career.
#2 Alexis Sanchez
Manchester United snatched away Alexis Sanchez from the claws of Pep Guardiola’s Manchester City in a player-swap deal involving Henrikh Mkhitaryan.
The Red Devils faithful were overjoyed with their acquisition, and Sanchez was tipped to be the man to take Manchester United back to the top of English football. There was good reason for their optimism as well.
That's because Sanchez had emerged as one of the best forwards in world football during his time at the Emirates. He was directly involved in 125 goals (80 goals, 45 assists) from 166 appearances for the Gunners.
However, things didn’t exactly go as planned in his United career. Sanchez never managed to hit the ground running at Old Trafford, and quickly fell out of favour under Jose Mourinho. The Chile international enjoyed a decent start to his United career, but could only register two goals and four assists from 27 appearances in his first full season at the club.
Sanchez was also deemed surplus to requirements by Ole Gunnar Solskjaer. and was allowed to leave on a free transfer to Inter Milan. The now-32-year old lasted just a shade above two years at Old Trafford.
#1 Juan Sebastian Veron
When Manchester United signed Juan Sebastian Veron in the summer of 2001, he was dubbed the next big thing in world football.
The former Argentina international established his reputation as one of the most exciting midfield prospects during his time at Lazio. Manchester United paid a then-British record fee of £38.34 million for the talented midfielder. But he could never adapt to life in England. The Argentine failed to nail down a starting spot under Sir Alex Ferguson, despite significant game time.
Veron made 82 appearances for Manchester United, which yielded a return of 11 goals and 11 assists. One of his main weakness was his inadequacy in coping with the physicality of Premier League football.
The now-46-year old was permanently shipped to Chelsea just two years after his United debut. Veron did not impress then-Chelsea manager Jose Mourinho either ,and eventually made the trip back to Argentina to sign for Estudiantes.