Lukaku, who arrived last month for a fee of £75m from Everton, has already claimed four goals in three games in a red shirt.
And Matic, despite having no real pre-season, has immediately asserted himself as a reliable, imposing lynchpin at the base of Mourinho midfield.
Speaking earlier this week, Giggs expressed his enthusiasm over the way United – and the newcomers especially – have kicked off their 2017/18 campaign.
“Henrikh Mkhitaryan already has four assists and that will do him the world of good, so hopefully he can get back to his [Borussia] Dortmund form.
“There’s a lot of players contributing to goals which is crucial to winning the league. Juan Mata scores year in, year out, Antony Martial chipping in and when Marcus Rashford and Mkhitaryan join the party you’ve got options. You can’t just rely on Lukaku.”
Mourinho has pin-pointed two areas that needed improvement and addressed them ruthlessly over the summer: a quick, powerful striker who won’t need time to settle in and somebody with big game experience capable of freeing up Paul Pogba further forward.
How often over the last few years have we seen glaring caveats in the side that haven’t been diagnosed, let alone dealt with?
But the Portuguese, in wonderfully pragmatic fashion, has found the perfect players to take this side forward, handpicking two of the best players of last season and unleashing them in emphatic style from day one.