Thibaut Courtois is one of Europe's hottest young prospects, a string of outstanding displays for Atlético Madrid have seen the Belgium internationals stock rise dramatically during his three-year loan spell in the Spanish capital.
At just 21 the scope for improvement is massive and could see him become the world's best keeper.
Courtios has played 91 times for Atlético and has won the Europa League, Copa del Rey and a European super cup along the way, as well as being voted LFP best goalkeeper for the 2012-13 season in which he had the lowest goals conceded per game ratio in the league.
Mourinho has already suggested that Courtois will return to Chelsea in the summer.
When being quizzed on possible arrivals from Atlético, he stated: "Courtois is our player, Diego is not our player, so I cannot speak about Diego Costa.
"About Courtois, I can, because he is my player."
The Portuguese is clearly keen for the young shot-stopper to return and this raises the question of whether or not he will dislodge Chelsea stalwart Petr Čech, who, at 31, traditionally still has his best years as a keeper ahead of him.
So, how then does Mourinho keep the men he calls "the best goalkeeper in the world" and "the best young goalkeeper in the world" happy at the same club.
It is difficult to imagine a Chelsea side without Čech in goal, he has been an ever present during Chelsea's greatest ever era winning three Premier Leagues, four FA Cups, two League Cups, one Champions League and last seasons Europa League. The Czech keeper has also kept a club record 210 clean sheets to date and is truly a club legend.
Surely then Čech cannot be dropped by Mourinho. Not necessarily.
'The Special One' has previous in this area. Upon arriving at Stamford Bridge in 2004 he removed Carlo Cudicini as the clubs number one and instated the then 22-year-old Čech. This was after Cudicini had been voted Chelsea player of the year in 2002 and was a fan favorite.
All this is before we even mention dropping club legend Iker Casillas at Real Madrid a decision which has been supported by Carlo Ancelotti since he took over at the Bernabéu. Mourinho will certainly not shirk the decision should Courtois impress suitably.
If he does not play the young Belgian the main issue Mourinho may face is the desire of Courtois to get first team football that he rightly feels he deserves. If reports are to be believed he has purchased a house in Madrid, and he is clearly enjoying being an integral part of an impressive Atlético side that is challenging for the Spanish title.
He has made it clear that he wants to play, stating: "It is not up to me to say I am going to be No. 1, but neither do I want to go to a team and not play. I want to play, if not at Chelsea, then at another team."
The youngster is resolute in his stance and knows he is good enough to succeed at any club in the world. If he can go to the World Cup and perform Chelsea may face a fight to keep him if they do not play him but this is unlikely to concern Mourinho who is no the type to surrender to player power.
The typical view on goalkeepers needing to be experienced to succeed has changed slightly in recent years. David de Gea, Joe Hart and Manuel Neuer have all been number ones at top level clubs before they turned 22 at Manchester United, Manchester City and Schalke respectively.
Whether Mourinho opts to stick with the experience and security of Čech or the exuberance and confidence of youth in Courtois one thing is for certain, Chelsea have two of the best keepers around and after 11 years of service from Čech if they can get the same out of Courtois their golden era may last a while longer yet.
Write for GiveMeSport! Sign-up to the GMS Writing Academy here: http://gms.to/1a2u3KU