The 21-year-old started the game at St Mary’s and helped the Red Devils to come from two goals down to salvage a point against the Saints.
Manchester United had found themselves 2-0 down inside 20 minutes but two quick-fire goals from Romelu Lukaku and Ander Herrera helped the Red Devils to earn a point.
Despite not getting on the score-sheet, Rashford proved his importance to the Red Devils by setting up both of his side’s goals.
And despite the obvious disappointment of not being able to claim the three points on the south coast, Mourinho felt that Rashford’s performance was one of the positives from the game.
Speaking to BT Sport immediately after the final whistle, Mourinho said: “I’m pleased with Marcus Rashford even without that (scoring).
“His work rate was amazing, he was doing things that others have to do, working out wide and trying to give solutions in midfield.
“The only thing that was missing was a goal but I can only praise him for his desire and respect for the shirt.”
Manchester United’s draw left them in seventh place in the Premier League table and 16 points behind leaders Manchester City.
They will now turn their attentions towards preparing for their crunch home clash against Arsenal at Old Trafford on Wednesday night in the Premier League.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news