Yaya being banned was probably a blessing in disguise. Fernando and Fernandinho pressed their balls off, ran around in 90 minutes and gave Roma midfielders no chance to play the ball around. Yaya would not be able to even do 20% of the pressing they did.
Yaya's been better in the last two weeks of course compared to his horrible start of the season, but I don't know how useful he'll be in the future against top CL teams. Becoming more and more of a luxury player for each year.
Fernandinho also kept running into Roma's penalty area, while Yaya would stay further back to spread the balls around. Made City's team much more mobile. Yaya is lacking mobility for a supporting striker role, and lack interest to defend for a CM role.
I just don't think it's impossible, that's all.