United were 1-0 winners in the Manchester derby on Sunday afternoon.
The two sides met at the Etihad on Sunday in a Manchester derby that was crucial to both sides hopes of securing a top four finish.
It was United who left the happier though, as a goal from youngster Marcus Rashford saw them secure all three points in a 1-0 victory.
The loss was the latest in a disappointing run of form from Manuel Pellegrini’s side, and Sinclair says he was not surprised by the result.
Questions are now being asked as to whether the announcement of the appointment of Pep Guardiola is the current cause of City’s malaise.
The Bayern Munich boss was named as Pellegrini’s replacement at the beginning of February and they have only won three of eleven games since then.
That run of form has seen them fall out of the title race, while their top four hopes are also under threat with West Ham United and Manchester United breathing down their necks.
And should they fail to finish in those Champions League places, many will question whether the announcement should have been delayed until the summer.