Ronaldo continued to dig United out of holes in the Champions League in midweek with a double in a 2-2 draw at Atalanta as he struck late to salvage points for the third time in four European games.
The 36-year-old now has nine goals in 12 games since returning to the club that first made him a household name.
Had things gone differently in the final days of August, Ronaldo could have been lining up in City blue for Saturday’s game.
Indeed it was City’s interest in the five-time Ballon d’Or winner that appeared to spark United’s move to sign Ronaldo from Juventus despite already boasting an over-subscribed array of talent for attacking positions.
Despite Ronaldo’s strike rate, the initially proposed deal to go to City might have been more beneficial for all parties.
Pep Guardiola’s men have shone at times this season, but have also missed a clinical finisher as they failed to score at home to Southampton and Crystal Palace to fall five points behind Premier League leaders Chelsea.
United are three points further back after a run of one win in five league games.
The Red Devils have won in just five of Ronaldo’s 12 appearances, while the likes of Jadon Sancho, Marcus Rashford and Mason Greenwood have been marginalised.
A 3-0 win at Tottenham last weekend bought Ole Gunnar Solskjaer some time as United boss.
But the defensive frailties that Liverpool exposed in a 5-0 humiliation of Solskjaer’s men less than two weeks ago were on show once more in Italy on Tuesday, especially after Raphael Varane limped off with a hamstring injury.