I don't think this match has any concern or connection on Rodri, because he is still on his sick bed and Vini will be on the pitch. The match means a lot for both teams not for only City, because City has no reputation to lose but Madrid will lose their reputation for being kicked out of UCL in group stage. Madrid has the strength to win this match and City looks weaker than they were in previous season. You should bet on City to win the match if you have the confidence in them.
The drama of Ballon d'Or happened months ago, and Rodri got a serious injury in early of season that costs him rest of season. This playoff pair between Real Madrid and Manchester City will not have participation of Rodri, and it's not like a revenge of Vinicius Junior against Rodri too.
Vinicius will fight in two matches with his teammates for a ticket to a next stage of Champions League, and to win another Champions League title. So far he has won 2 UEFA Champions League titles and is going to chase a third one. Winning Champions League title in years without World Cup or Euro tournaments are vey big points for winning individual award like Ballon d'Or.
Ballon d'Or rivalry has nothing to do with the Champions League. So when Man City has to play against Real Madrid it is not an individual battle between Vini and Rodri because it will always involve many people, and their existence and contributions are much more important than Vini or Rodri.
Talking about opportunities, Real Madrid seems to have a better chance than Man City, because they are not as bad as Man City. It's just that there is one thing they don't do when they have a chance, which is not to bring in new players (especially defenders), though Ancelotti should know very well that their defense line really sucks.