Speaking to the media ahead of Sunday's clash at Old Trafford, Newcastle manager Eddie Howe said: "We're trying to provide long-term growth, we've got a longer-term vision.
"At the moment, we have quite an ageing squad, so we need to invest more in young players. Cristiano Ronaldo might not be a signing that we would necessarily look to make.
"But that's not under-estimating the quality of the player. He's an outstanding player. You look at his goal record last year (36 from 44 games), that was incredible. So, for me, the transfer has worked, it's been a success.
"He got massive goals last year and some really late, important goals in the Champions League. The quality of the player is unquestionable. We are going to have to be very, very good against him if he plays."
Saudi-owned Newcastle are one of the few clubs in the world who can theoretically afford to sign Ronaldo and pay his salary.
The 37-year-old is expected to make another push to leave Manchester United in January after falling down the pecking order at Old Trafford.
