I hate this narrative from so many (not meaning to pick on you but this POV is representative) that Jack should do all the hard work and then Doku should come on when defenders are tired to prance about and get an easy assist/goal.
Firstly, any City fan should know that Jack HATES being taken off before the full 90 and he's already struggling for confidence after the number Pep's been doing on his head this season, pitting him unnecessarily against St Jeremy, especially as he was coming back from injury (some prize prickishness from Pep IMO, not to mention completely counter-productive with regards to Jack).
Secondly, why should St Jez get such favourable treatment? He's been with the club five minutes and been distinctly average to invisible in the couple of difficult games he's played (Arse and Chelsea). Jack was an essential part of our winning the treble so it would be nice if City fans could make an effort to give him the respect he deserves. He should be allowed to get confidence and rhythm without being sacrificed to benefit the shiny new toy.