According to the club’s latest quarterly financial results, the decision cost the club £16.7 million coming just a year after the club spent £14.5 million to part ways with Erik ten Hag and his coaching crew.
Amorim’s exit came with 18 months still left on his contract and followed a poor run of form that left United in a difficult position.
However, the financial impact has since been partially offset by improved performances under Michael Carrick, who has overseen a major turnaround in results.
Carrick guided United from 15th place last season to a third-place finish, securing Champions League qualification and boosting future revenue prospects.
While matchday and broadcast income remained stable, sponsorship revenue dropped 9.4% to £38.5 million due to the expiry of the Tezos training kit deal.