Solskjaer confirmed that Ronaldo will play against the Magpies, but did not give away whether that would be from the start or from the bench.
In his Friday press conference, Solskjaer said: He's [Ronaldo] been having a good pre-season with Juventus, he's played for the national team.
"He's had a good week with us here and he'll definitely be on the pitch [against Newcastle] at some point, that's for sure."
Ronaldo has spent a lot of his career on the wing but, as he has got older, he has moved centrally and played as a striker, more often than not.
Former United defender Mikael Silvestre thinks Ronaldo will play that role for the Red Devils, and that he will continue to score goals, despite coming into the twilight of his career.
"This is a magnificent signing," Ronaldo's old teammate told talkSPORT.
"Even at 36, I think he will be a massive player. He will add so much firepower upfront.
"As a No.9 he became more and more of a finisher over the years and his statistics are amazing. Over the last ten years, he has scored more than 20 goals [a season].
"He is still amongst the top goalscorers in Europe. He assists as well, free-kicks - I just wonder who is going to take penalties with Bruno [Fernandes] there."
Silvestre isn't wrong. In fact, Ronaldo finished last season as Serie A top scorer with 29 goals - more than Chelsea's big-money summer signing Romelu Lukaku who finished with 24 for champions Inter Milan and cost £97.5million.
He's now set to make his second debut against Newcastle after the international break.
But how will Ronaldo's teammates, including Portuguese countryman Fernandes fit in around him?
There is no question about who will play as United's No.9, but there is still some debate about their No.1.
Dean Henderson and David de Gea battled to for a starting spot throughout last season and it appears the latter is Solskjaer's choice this campaign.
Their back four now, pretty much, picks itself after the signing of Real Madrid defender Raphael Varane.
Luke Shaw and Aaron Wan-Bissaka will flank defensive superstar Varane and United's £80m man Harry Maguire.
Just in front of them is where it gets slightly trickier.
Scott McTominay could be absent after groin surgery and may not be rushed back to face the Magpies.
Fred may also be banned, leaving Nemanja Matic as the holding midfielder until the Scotsman and Brazilian return.
Meanwhile, with Ronaldo an additional forward, Paul Pogba, who has started to show what he can really do in a red shirt on the left of midfield, will play in a slightly deeper role again, behind his mercurial companion Fernandes, who features as a No.10.
Then, on the wing, Jadon Sancho, who was signed from Borussia Dortmund this summer for £73m will play on the opposite side to either Mason Greenwood, with Marcus Rashford injured.
The latter is expected to be out of action until October after undergoing shoulder surgery, so Greenwood has an opportunity to prove that he is capable of being a starter for United - something which he has done so far this season.
Then, of course, you have Ronaldo through the middle which, completes a pretty formidable XI that Toon boss, and former Red Devil, Steve Bruce will have to deal with.
How Manchester United could look against Newcastle
Download talkSPORT Edge NOW!
Whether it's goals as they go in or the latest from your club, stay up to date with everything going on in football with breaking news, live scores and in-app betting.
Download talkSPORT Edge in the App Store here.