The 19-year-old striker broke the deadlock after just eight minutes at Old Trafford on Saturday and he was a handful throughout for the Premier League leaders.
Are you the next great English Premier League Fantasy Manager? Play our Match of the Week Fantasy Game, challenge your friends and win great prizes!
Rashford was on set-piece duty for the Red Devils in the absence of Juan Mata and Daley Blind, and Mourinho says the decision to give him such a responsibility ahead of his peers comes down to trust.
The United youth product has been used sparingly this season, but seized his chance when called upon with two goals from four starts in the last five Premier League games.
When asked why he chose Rashford for the role, Mourinho told MUTV: “Marcus is trustable.
“Even for the second goal, his free-kick was really high, impossible to score from a header because it was to what we call the third post – not the first or second post.
Don’t miss the FIFA U-20 World Cup 2017, starting 20 May, LIVE on Kwesé Sports.Get Kwesé TV now in Ghana, Zambia or Rwanda. To enjoy our streamed free channels, viewers all over Africa can download the Kwesé App for iOS or Android or register online.
“But he’s always tense, he’s always fast, and you can always trust that [he will make] strong contact with the ball.
“The ball always goes with speed with him. With some other guys, the ball goes in the right spot but slower. Even if you win the duel in the air, it can be really difficult to score, so in this moment Marcus is one of the boys we trust.
“Because he’s so young, he’s able to keep developing that day after day; he’s always with one of the assistant coaches trying to make it even better.”
Connect to Kwesé TV now in Ghana, Zambia or Rwanda. Africans outside these territories can download the Kwesé App, or register online, and enjoy our offering of streamed free channels.