In a sudden, and shock, move, Matic left the Premier League champions as Manchester United snapped him up for over £35m.
That’s now seen as a bargain, with Matic arguably Man United’s best player thus far this season.
Many were surprised that Matic was allowed to join United with such ease, including his manager Mourinho.
“I was surprised when [Matic’s] agent called me to say ‘do you want him?’ ” Mourinho told Sky Sports.
“I was surprised, but he’s an agent I know well. Normally he’s very direct and objective, he doesn’t waste time, he doesn’t try to get people to be interested in his players to improve their situation at their club.
“Normally he’s very straightforward, so when he told me ‘you can have him if you want’, of course I want.”
Rarely a week goes by without a former-footballer turned pundit slamming Chelsea’s decision to let Matic travel up the M6 to Old Trafford and sign.
The Serb has been thoroughly impressive in Red, so far. His presence helped specific players, most notably Paul Pogba and Marouane Fellaini, at the start of the season and now with that pair both suffering injuries, Matic has been the reliable and consistent performer in the middle of the pitch, no matter who plays alongside him.
There have been absolutely no troubles settling in, and while Romelu Lukaku struck 11 times in his first 11 games for the club, few would argue that Matic wasn’t United’s best signing of the summer.