Just how much can a transfer fail?

Back in 2014, after a disastrous season under David Moyes, Manchester United attempted to ignite the post-Sir Alex Ferguson era by spending some cash.

The big signing was Angel Di Maria who cost them a then British-record fee of £60m - a huge investment.

Di Maria had just starred for Real Madrid and was one of their most influential players as they won their 10th Champions League trophy that May.

United had pulled off a great signing then and Di Maria was immediately handed the number 7 shirt - the most prized at Old Trafford.

Fast-forward to the end of the season and Di Maria's stats looked like this - 20 starts, three goals, ten assists.

Which isn't exactly dreadful but far from the seven goals, 22 assists he'd managed the season before which had led to United signing him.

In fact, Di Maria was considered so disappointing that the Telegraph named him the worst signing of the season for the entire Premier League.

And so, in the summer of 2015, United sold Di Maria to Paris Saint-Germain for £44m - a £16m loss on a player signed a year previously.

The Argentine clearly didn't enjoy his time at the club - as evidenced by his failing to board their plane for pre-season that summer - and that's a grudge he's held onto.

Because according to PSG goalkeeper Marcin Bulka, Di Maria won't even watch United on TV.

"Di Maria hates Manchester United," he told a Polish Youtube channel (per A Bola). "He has no good memory of the time he spent there.

"In fact, when something related to Manchester United appears on television, it changes soon."

Even when something related to United - they don't even need to be playing.

When United paid that £60m for him, they probably didn't envisage that six years later, he'd detest the club so much that he won't even watch people talking about them.

That's about as bad as a transfer can get.