In October, Argentina lost a friendly match 2-0 against Brazil in Beijing and Di Maria played the full 90 minutes.
The air quality was not great, the temperature was high and three days later he featured for the final 17 minutes of a friendly against Hong Kong national side.
The round trip was approximately 12,000 miles, and for a player who had not had much of a summer break because of his international commitments, and had finished the World Cup with a thigh injury, the Far East trip must have been physically draining.
In addition, United manager Louis van Gaal's search for his best formation- and Di Maria's best position in it- meant there was little continuity in his role.
In the South American's first 16 games for the Reds, he played in six different positions including the unfamiliar role of central midfielder and striker.
Consistency continued to prove elusive, and Di Maria's contribution seemed to be affected as a result.
As well as his goal drought, he created only three goals in four months between October 2014 and February 2015.
A pelvic injury kept him out for virtually all of December.
So a likely combination of fatigue, injury, lack of form and getting used to a new country and language difficulties could all have been playing on his mind when he suffered a break-in at his Cheshire mansion in January.
The intruders did not gain entry and no-one was harmed, but the impact on him and his family was so great that they are now living in a city-centre apartment.
On the pitch, Di Maria's slide continued and, sent off in the FA Cup quarter final defeat by Arsenal in March, he was a substitute in six successive games following his return from suspension.
He did start the final game of the campaign at Hull but limped off injured after 23 minutes, somewhat synonymous with his final days at the club.
This combination of circumstances led to Di Maria becoming extremely unhappy and wanting a move, but as recently as Sunday, LVG said he hoped Di Maria would stay.
Yet the Dutchman has also stated that it's counterproductive to keep unhappy players, PSG were keen on taking him last year and are now offering a get-out.
United fans have been here before (think Seba Veron and the then record signing Dimitar Berbatov, who left for Fulham six months after winning the Golden Boot).
Yet possibly more than those two, Di Maria's imminent exit will leave a sad sense of "what might have been" purely because his talent has been so obvious in the past and his exit so swift.
When you sign a player as good as him , you have to give him more than one season to adapt and settle.
He proved he had the ability and wow factor that United needed, he proved he can play under LVG, now he's leaving and it is hugely disappointing.