The Magpies travel to Old Trafford knowing that the Portuguese icon could feature for the first time since completing his summer transfer from Juventus.
Steve Bruce’s men are still waiting on their first win of the season, but did pick up their first point of the campaign in a dramatic 2-2 draw against Southampton just prior to the international break.
For their part, Man United are still yet to lose in the Premier League, taking seven points from their first three matches.
And Stelling believes that they will keep their unbeaten run going this weekend.
Speaking to Sky Sports’ Super 6, the Soccer Saturday host said: "The return of Ronaldo.
"The first time Cristiano Ronaldo graces the Old Trafford pitch after signing from Juventus, unfortunately for Newcastle, could spell trouble.
"I think he may be on the scoresheet and Man Utd will make it a tough afternoon for former Red Devil Steve Bruce."
Stelling predicts a 3-0 defeat for the Toon Army.
Fellow Sky pundit Neil Mellor is also of the opinion that Newcastle will lose, forecasting a 3-1 victory for the hosts.
The Magpies have lost their last three meetings against the Reds, conceding at least three goals on each occasion.
The most recent clash between the two sides came back in February, with Marcus Rashford, Dan James, and Bruno Fernandes finding the back of the net to cancel out an Allan Saint-Maximin consolation strike.