Samir Nasri, who moved on loan to Sevilla in the summer, revealed the strict rule designed to curb muscle injuries.
Players are allowed to stay at home the night before matches at the Etihad but have been told they must not have sex once the clock strikes 12.
Nasri said: ‘Relations must be before midnight, even if you have a free day the following day. It’s so you can have a good night’s sleep. He told us this is how he got the best out of Lionel Messi and Robert Lewandowski, and for them to avoid the maximum number of muscular injuries.
‘Guardiola will not bully you but he will do everything to make you progress. He is a picky person.’
Guardiola has also cut WiFi in areas of City’s training base to foster team harmony and introduced group meal times.
Original source: No sex after midnight for City players