Ronaldo returned to United this summer but there was a chance to bring him back to Old Trafford in 2018, while he was playing for Real Madrid.
Mourinho and Ronaldo previously worked together for three years in the Spanish capital, and Jim White of talkSPORT claimed former Vice President Ed Woodward wants to broker a deal.
White explained: “Over the years there has been a lot of discussions about Ronaldo’s return to Manchester United.
“Maybe it happened when he finished at Real Madrid, when he was still at his prime.
“But that was not possible because Jose Mourinho made it clear that at the time he had other priorities.”
That summer, Ronaldo instead moved to Juventus, where he stayed for three years before returning to England in August.
Meanwhile, Mourinho had just led United to second in the Premier League table and was desperate for the club to sign a central defender. Toby Alderweireld and Diego Godin as well as Jerome Boateng.
This is probably the reason why Mourinho chose against Ronaldo’s transfer.
Instead, United signed Fred and Diogo Dalot and a poor start to the season saw Mourinho sacked in December.
Ronaldo’s comeback was a strong figure, with the five-time Ballon d’Or winner scoring 24 goals in all competitions.
But United finished sixth and failed to qualify for the Champions League with 58 points – their lowest level ever in the Premier League.
Six first-team players left at the end of the season and new coach Erik ten Hag appears set to complete his first signing.
A deal has been agreed for Feyenoord’s full-back Tyrrell Malacia, while negotiations continue with Barcelona in favor of Frenkie de Jong.
The 25-year-old has worked under Ten Hag at Ajax and will play a vital role in United’s new system.
Ten Hag underwent his first training session on Monday and his philosophy came out.
He worked with a number of the academy’s alumni and confirmed that he wanted a high pitched beat.