Last week Ronaldo seemed destined to join Manchester City after Jorge Mendes held talks with the Premier League champions over a potential move.
But Manchester United intervened at the last moment and former Red Devils and Sir Alex Ferguson spoke with the 36-year-old to steer him towards returning to Old Trafford.
Ronaldo is set to make his second debut for Manchester United against Newcastle after the international break and Sinclair conceded that he is pleased that the Portuguese went to the red side of Manchester.
The former Manchester City star admits that he respects Ronaldo for not joining the Premier League champions as it would have spoiled his special relationship with Manchester United and their fans.
Sinclair said on talkSPORT: “I have never disagreed with that [Ronaldo is going to do well at Manchester United].
“What I did say that I think he would have been more successful at Manchester City, but I respect him for not going to the blues.
“He has got a huge amount of fans who support him at Manchester United and I feel he would have burned a few bridges if he went to Manchester City.”
Ronaldo is set to return to England early from his international duties as he is suspended for Portugal’s World Cup qualifier against Azerbaijan next week.
