Ronaldo recoded 118 goals in 292 games over six successful years in the North West in his first stint with Manchester United.
The 36-year-old is set to make his Man United debut after completing his move from Juventus against Newcastle on Saturday.
And speaking on his returned to Man United, the five-time Ballon has insisted he has not come to spend vacation at Old Trafford.
"I am capable," Ronaldo told the club's official website. "I am ready to go.
"This is why I am here," he said. "I am not here for a vacation.
"Before was good, winning important things and I wore the shirt before, many years ago, but I am here to win again.
"It is a good chance for me, for the supporters, for the club, to get one step ahead. I am ready and I think I will be a huge thing in the next three or four years."
The Red Devils finished second last season, albeit 12 points behind champions Manchester City but have boosted their title hopes with the re-signing of fans’ favorite Cristiano Ronaldo as well as Raphael Varane and Jadon Sancho.
Ronaldo completed a £19.8 million move to United from Juventus earlier this week, having left Old Trafford for Real Madrid in 2009 for a then-world record fee of £80 million.
The Portuguese forward will be wearing his iconic number 7 shirt in his second spell at Old Trafford.
