Joe Hart has signed for Tottenham Hotspur on a two-year deal, becoming Mourinho's second signing of the summer window.
The experienced goalkeeper has reportedly taken a pay cut and will be on £27,000 pounds a week.
The deal has shocked the football world and appears to have happened overnight.
Does the deal make sense?
Despite the shock when you first see it, the deal does make sense. Michel Vorm left the club in the summer, leaving only Paulo Gazzaniga and Hugo Lloris as options.
He will most likely be third choice in the pecking order, possibly second, but with the demands of the Europa League looming – Spurs will need as many as they can get.
Also, he represents a homegrown spot. Spurs now have too many players who do not count as homegrown, which restricts the size of the squad they can name.
What will he bring?
Despite the fact he will not play many games, he will bring qualities to the squad that will be more than useful.
Under Manchester City, he has won the Premier League twice, FA Cup once, the League Cup twice, and has four golden gloves.
The goalkeeper has also represented England 75 times, where he featured in the UEFA Euro 2012 and the 2014 World Cup.
This type of experience, a man who has 'been there and done it', will provide telling considering a majority of the squad haven't got the experience of winning major trophies in England.
The Spurs team has often been called out for a lack of leadership – Joe Hart is renowned for exactly that.
His career began it's downward spiral when Pep Guardiola came into Man City, since he has moved around from Torino, West Ham United, and Burnley.
His fall from grace has been tough, but he still brings qualities that could show this to be a successful signing.
Hart in the right place
Speaking to Tottenham's club website, the 33-year old said:
“Firstly, I just want to say thank you to the Club for seeing something in me,” he said. “No getting away from it, it’s been a difficult couple of years for me personally on the football field, but I feel I’ve got so much to give, I feel like I’ve got a lot of quality, a lot in the bank, but not much game time recently.
“I can only look at things positively. I’m ready to go. I feel like I’m starting again, and I quite enjoy that feeling. My body is certainly ready for me to start again. I’m ready to push and ready to get back to levels. I love the idea of European football, two games a week... it all excites me.”