Premier League football returns this weekend following the international break, with United travelling to face last season's runners-up on their own patch.
Much of the talk around the fixture has centred on Ronaldo, who could make his second debut for Ole Gunnar Solskjaer's men after rejoining the club from Juventus in the summer transfer window.
But Bruce wants his side to focus on the task in hand, with the Magpies yet to register their first three points of the campaign – and he is hoping the clash with the Red Devils will see his charges seize their opportunity to "spoil the party" at the home of the club he captained with distinction in the 1990s.
"It's always going to be tough, and obviously the added spice of Ronaldo coming back has added to it," he said.
"But make no mistake, they've got quality players all over the pitch, so whenever you go to Old Trafford the one thing you’re going to have to do is enjoy the challenge of playing against one of the big, big teams in this country – and relish the opportunity to go and see if we can spoil the party a bit."
Newcastle will have to do without the services of injured duo Callum Wilson – who has netted twice in three outings so far this term – and Ryan Fraser, with head coach Bruce confirming both players will miss the game.
But United have received some positive news regarding Miguel Almirón, who will be available for selection.
"Callum won't make the weekend unfortunately. He picked up a thigh injury, a muscle strain, so he won’t make it," said Bruce.
"Ryan Fraser won't make it either. He's twisted his ankle. We don't think it's as bad as certainly photographs that were seen, with him on crutches and in a boot – it was pretty precautionary – but he'll not be ready for the weekend either."
On Almirón's situation, Bruce added: "It's a difficult one for the players, because all they want to do is play football. The ultimate is to play for your country and I can understand that, and of course play on a Saturday, so they've been drawn into a very difficult situation.
"However, a bit of common sense has prevailed with Almirón in that he's available, so we're extremely pleased that he's available for selection."
Meanwhile, goalkeeper Karl Darlow is nearing a return to action as he works his way back after suffering from COVID-19.
Bruce admitted he has a decision to make about his stoppers ahead of Saturday’s game, with Freddie Woodman having deputised for Darlow and the injured Martin Dúbravka so far this term.
"He's trained the last week ten days," he said of Darlow. "There's been a big improvement in him, which we're all delighted about.
"He's put himself in contention – whether he's quite ready to start, I'll have to make that decision in the next 24 hours or so.
"But we're just pleased that he is back training with us and he looks a bit more like himself, which is good to see."