The 36-year-old rejoined Manchester United last month in a sensational move where Sir Alex Ferguson played a role in bringing him back to Old Trafford, 12 after he left the club in 2009.
Manchester United have agreed to pay an initial fee of €15m over five years and is now the highest-paid player at the club.
Ferguson feels the Manchester United owners were under pressure after all the protests last season and pulled out the big deals to appease an irate fanbase.
He stressed Ronaldo still has enough quality to deliver the goods for the Red Devils and believes despite his advancing years, he will be a proven goalscorer for Manchester United this season.
Ferguson said on The Go Radio Football Show: “I think the Glazers had to do something because the Man United fans were not happy with all the breakaway stuff that was going on.
“They have pulled it out with big signings and there is no one bigger than Ronaldo.
“I know he is 36 but he looks after himself and you will still get great quality.
“He is not the same player he was before.
“He predominantly played in the wide areas but now he plays through the middle.
“But he has still come to Man United to score goals.”
Ronaldo is set to make his second debut for Manchester United on 11th September when they will host Newcastle United at Old Trafford.
