#4 Ander Herrera
The 28-year-old Basque midfielder has a mixed United career, to say the least. After struggling under Louis van Gaal for two seasons, the arrival of Mourinho brought about a transformation.
Herrera won United's Player of the Year award, helping the Red Devils to three trophies from a deeper role in midfield and was even called up by the Spanish national side.
However, the arrival of Nemanja Matic last summer created an issue as he's struggled for regular minutes, seeing his performances dwindle in terms of consistency as a result. He's only managed to start ten Premier League matches this campaign, which is disappointing on a personal level after reaching such heights in the past.
Mourinho has claimed he will look to sign around 2 midfielders in the summer. That - alongside Scott McTominay's rise - could cause Herrera to reconsider his future at the club.