The 31-year-old was handed just his second Premier League start since Christmas, whilst Martial was given a chance to feature at No.9 for the first time since January.
And the pair combined brilliantly at Turf Moor, with Martial claiming Man United’s first goal after 21 minutes before teeing up Rooney to double the advantage just before half time.
Rooney, speaking to Sky Sports, noted that he and the youngster had given Mourinho something to think about heading into an important series of games.
“We knew this was a difficult place to come after going from the high of getting to the Europa League semi-final to the low of losing Zlatan and Rojo,” he said.
“We’re all gutted for both of those players. We wish them a speedy recovery.
“That gives other players a chance to come in and try and stake a claim, like myself and Martial have given the manager something to think about.
“We played well, both scored so it’s great. It’s competition for places and that’s what we need.”
With Marcus Rashford left on the bench and Zlatan Ibrahimovic injured, Mourinho presented supporters with a new, untried attacking dynamic against Sean Dyche’s men: a more fluid, less structured set-up, with Jesse Lingard sticking militantly to the right whilst Rooney and Martial operated as a duo, interchanging positions with admirable alacrity.
What this created, in turn, was an unpredictable, open set-up engineered towards punishing opponents on the break, and that is exactly what Mourinho’s men did on Sunday afternoon.