Mourinho expressed disappointment this time previous year when Pereira, who had spent the 2016/17 season on loan with La Liga side Granada, chose to pursue another loan with Valencia instead of fighting for a first team place at United.
Manchester United midfielder Andreas Pereira says loan spells at Spanish sides Granada and Valencia over the last two seasons have been crucial to his improved performances at the Premier League club.
The 22-year-old impressed in a Valencia team which finished fourth in La Liga and returned to Old Trafford full of confidence after a full season of regular playing time in Spain. "They've been really good for me, I think I've totally changed as a player and a human being after these two years", he added.
"It was very hard for me to take that decision".
"We had a great year in Valencia, and I am a better player, and this season he has a better Andreas than he could have had last year".
Pereira told Sky Sports: "I learned a lot of things being on my own, I lived on my own there, and it's different than living over here".
And the gamble appears to have paid off for Pereira after he started United's Premier League opener against Leicester and featured heavily in pre-season under Mourinho.
"I have a very good relationship with him, he is very good with me, very honest". Pereira played for the Belgium under-15s, U16s and U17s before opting to represent Brazil at the U-20 World Cup in 2015. "I knew in the same way, when he came back from Juventus, he'd be the same old Pogba".