Carlos Fernandes, Jorge Vital, Adelio Candido, Emanuel Ferro and Paulo Barreira have moved to Manchester alongside Amorim, with the five coaches joining Darren Fletcher, Andreas Georgson and Craig Mawson in the set-up.
Amorim previously described Fernandes as his "Jose Mourinho", and the 29-year-old is moving to the Red Devils as assistant manager.
"My number two is Carlos Fernandes, he's been my right-hand man right from day one," said Amorim in an interview back in 2022. "He'll be a much better coach than me. I often say if I become Bobby Robson, then he'll be my Jose Mourinho! But there's plenty of time, we've signed a 15-year deal!"
Man United confirmed earlier this week that Ruud van Nistelrooy, Rene Hake, Jelle ten Rouwelaar and Pieter Morel had left the club following the arrival of Amorim, with a number of changes being made to the backroom staff.
Vital is arriving as the first-team goalkeeping coach, and he is set to work with assistant Mawson, while Candido's move has also been confirmed as a first-team coach, although the 28-year-old's visa still needs to be finalised.
Fernandes will be Amorim's assistant manager at Old Trafford
Ferro will be another first-team coach, while Barreira has arrived as physical performance coach, and he is familiar with English football following his time at both Arsenal and Liverpool.
"Manchester United can now confirm the arrival of five coaches that join the club as part of Ruben Amorim's backroom team," read a statement from the 20-time English champions on Saturday.
"Carlos Fernandes, Jorge Vital, Adelio Candido, Emanuel Ferro and Paulo Barreira have all made the move from Sporting to United with our new head coach, who began work in Manchester earlier this week."
Fernandes posted on Instagram last weekend: "So many moments that I will cherish forever. There is no other feeling other than eternal gratitude towards those who helped us create something so special: players for whom there are no words, colleagues who became friends and everyone who always supported us. THANK YOU VERY MUCH."
Amorim is still yet to receive his visa, but it is expected to be confirmed in time to allow him to take training for the first time on Monday, with Man United building towards next weekend's Premier League clash with Ipswich Town.