Oh yes you do! If needed, that is exactly what you are going to do. I repeat, if needed, for those who need it -which is Guardiola's call.
You follow objectives, and you set your priorities accordingly. The league title is already won, I do not give a fuck (neither does History...) when City will win it mathematically. But we're talking about a CL QF here. You fuck up there, you won't be able to fix it. The opportunity is lost permanently, you'll have to wait for next season again...
These players have worked their asses off to achieve such an advantage. Some of them may need protection, we'll see. Obviously the result of the 1st leg is expected to play a major role in this, the injury status of the squad, individual form etc. What I mean is that, in any case, this is a luxury City can afford, while Liverpool cannot. Their CL football next season is a question mark at the moment, with Chelsea 4 points behind, and 8 matches to go. So they are obliged to give everything on both competitions -another factor that could have an influence in the matches between us...
I think back in the early 70's city were due to play Chelsea in the European Cup Winners Cup and we had a league game just before it that wasn't important. Malcolm Allison wanted to rest Colin Bell; Joe Mercer said you always played your strongest side...... Bell got injured in the league game.... I remember under Stuart Pearce when Samaras was our main hope against West Ham in the FA Cup and he got injured the game before when perhaps he should have been rested.
For me, resting players so that they are available for the 'must win' games (whether league or cup) is essential - we won't get a second chance in the CL whereas the United game is not that vital given the run in we have.
I also think that psychologically we need to turn the Liverpool fixture 'hoo-doo' around - its long overdue and this is our best ever chance, especially now that the Arsenal hoo-doo has been put to bed at long last. We have a fantastic chance to step-up here.........