Jones and Smalling returned from injuries sustained after colliding during an England training session in March, and Mata miraculously returned from a groin injury earlier than expected after Mourinho had stated last month that he would be out till 'late May.'
"I think [Phil] Jones, [Chris] Smalling, [Juan] Mata, they were amazing in the way they performed. They showed amazing effort and attitude after seven weeks without playing football due to important injuries," said Mourinho.
"I feared that the players could not play for 90 minutes. I feared that my changes - instead of being to change Herrera and Mkhitaryan, players who played 90 minutes in Vigo, I feared that I would have to change Mata, Jones and Smalling. But they were fantastic.
"I think this game is a plus for them, to play 90 minutes is fantastic because now we have three Premier League games to play plus the semi-final and let's hope we have one more game to play."