Manchester United manager José Mourinho has opened up about his touchline dispute with Nemanja Matic while the pair were at Chelsea.
Mourinho brought the Serbian on as a substitute during a 3-1 defeat to Southampton at Stamford Bridge, giving him just half an hour's play before bringing him back off.
It is undoubtedly one of the most galling things that can happen to a footballer, and Matic couldn't hide his anger about the incident.
After signing Matic for the second time, following his move from Benfica to Chelsea in 2014, Mourinho has said that the midfielder's reaction left a lasting impression on him.
The Portuguese said that he showed his mental stability with the substitution, which is clearly one of the reasons why he brought him to Old Trafford in one of the most high-profile transfers of the summer.
And Matic's reaction to it has clearly stayed with him.
"I cannot say I have had better guys in my career," said Mourinho.
"The press wants a story, the press wants blood. My blood, or his blood, or both.
"He was really sad. I was also sad because it's not something nice and it's something I did only twice in my career.
"But the next day he comes to see me and he says, ''I'm not happy, but it's my fault. I'm not happy with what you did to me, but it's my fault, because the way I was playing I can understand the change. So let's keep going.""
Just over two months later, Mourinho was sacked as Chelsea boss, having steered them to the Premier League title just seven months previously.
However, he was keen to work with Matic again, as he looked to bulk up his Manchester United squad following last year's sixth-placed finish.
"We didn't keep going for a long time because a few weeks later I was sacked," the Portuguese continued.
"'But again he was one of my guys, was one of the guys that we kept close during these years even not working together.
"So I know that the big man is there, even with more maturity."