The Blues have come under fire for removing their talisman from the matchday squad twice in the run-up to European clashes, with the striker not even on the bench for trips to Stoke City and Aston Villa respectively.
He went on to start against Viktoria Plzen and Bayern Munich just days after being dropped.
It is a controversial and high-risk strategy which the results are yet to justify - City drew 0-0 at Stoke City, lost 3-2 at Aston Villa and were humbled by Bayern. Only the journey to minnows Plzen mustered maximum points.
But a source at City confirmed that manager Manuel Pellegrini has no intention of reversing his policy, saying: "Not only does the boss want to keep Sergio fresh for the European nights, there is also a feeling at the club that Sergio is always on the brink of another injury.
"The problem is, Sergio couldn't stay fit last season for any length of time and to make matters worse, this summer he didn't kick a ball in anger throughout pre-season because he was injured again.
"It is a case of playing catch-up all the time and resting him before the European games eases him back into the cut-and-thrust of top-flight football gradually.
"Obviously on the outside it is seen as a gamble because league results are patchy and most fans would make regaining the title from United the top priority, above European success.
"But until Sergio reaches peak condition and gets a bit of a rhythm going, nobody should expect a sudden change to the selection policy."
City head to CSKA Moscow on 23 October, four days after an away clash with West Ham United.
Source: Manchester City MAD