The club is experiencing a tough start to the season, with a 14th-place ranking in the Premier League and an early exit from the Carabao Cup at the hands of League Two team Grimsby.
Amorim, a highly respected coach, has faced criticism for his team's performance and his decision to stick with a 3-4-3 system. His job security has been questioned, with some speculating that he may face the risk of being let go if results don't improve.
The 3-1 defeat to Brentford on September 27 was the latest setback in a string of disappointing results since Amorim took over.
The team gathering was reportedly a regular occurrence for Manchester United, with this particular event happening just one day after the Brentford loss.