The Portuguese boss has begun shaping his United squad with three new signings - Eric Bailly, Henrikh Mkhitaryan and Zlatan Ibrahimovic - already complete and a fourth, thought to Paul Pogba, on the horizon.
Reports had suggested a number of players could face the chop as Mourinho trimmed his squad.
The report says Mata, who was sold by Mourinho in 2014 to United when at Chelsea, will remain at the club with the 53-year-old believing he can get the best out of the Spaniard, albeit as a rotational player and not a regular starter.
Jose Mourinho puts Manchester United stars through their paces in pre-season training
Fellaini has had a difficult time since joining United in 2013 but it is claimed Mourinho wants to keep him for his aggression.
While Blind, who revealed his disappointment at the sacking of Mourinho’s predecessor Louis van Gaal, will get a chance to show his versatility, which allows him to cover in a number of positions.
We use your sign-up to provide content in ways you've consented to and to improve our understanding of you. This may include adverts from us and 3rd parties based on our understanding. You can unsubscribe at any time. Read our Privacy Policy