I understand why you feel this way, but still think Matic would be a gamble. It even took Fernandinho a bit of time to really be himself in the PL, and I don't think Matic is as good as Fernandinho. I just think it would be a gamble, and sometimes gambles do pay off.
I'm not sure if he's the right kind of player versus City, though, I'd be eager to know why you think that. I feel a lot of teams obsess about Yaya's strength, but I think Yaya is better nullified by a bunch of small players running around him versus trying to match his steel. I certainly think that our struggles, when we have struggled, have correlated with quicker sides using pressing and pace to make things difficult, not necessarily strong DMs breaking up play. If we've passed our way to the DM, in most cases you're already in far too much trouble for him to do much. I suppose if you play with two CDM then maybe this isn't true, but we've been far better against the packed bus this year than previous seasons. I think Chelsea will have to possess the ball to win this one, but I suppose it's plausible Jose will play for the draw.