The 37-year-old has been vocal about his desire to leave the Premier League club this summer after Manchester United failed to secure Champions League qualification.
Ronaldo scored 24 goals across all competitions last season but he failed to guide Manchester United to a trophy or a top-four finish.
The player is now looking for a new challenge and a deal with Sporting Lisbon is close to being completed.
According to an exclusive report from Caught Offside, the Portuguese international could be presented as a Sporting Lisbon player before the end of the week. His agent Jorge Mendes has been working around the clock to finalise his client’s return to Lisbon this summer.
Ronaldo made an emotional return to Manchester United last summer but the move has clearly not worked out for either party and it will be interesting to see how the move to his boyhood club works out now.
The 37-year-old is still a world-class player who is capable of playing at a high level and his decision to return to Sporting Lisbon is a bit of a surprise. A player of his calibre should be playing for a club capable of winning the Champions League and Sporting Lisbon are certainly not at that level yet.
Meanwhile Manchester United will have to bring in a quality replacement should Ronaldo move on and they have been heavily linked with a move for the Ajax winger Antony.