Manchester City have a nightmare task on their hands rescheduling upcoming matches against Chelsea and Manchester United if their Covid-19 outbreak forces them to postpone both fixtures.City had no choice but to ask the Premier League to postpone their clash with Everton on Monday night after another five of their players contracted coronavirus.Their latest blow came after Kyle Walker, Gabriel Jesus and two members of staff tested positive on Christmas Day, meaning none of them could be involved in their Boxing Day victory against Newcastle.And on Monday Pep Guardiola was dealt another setback, which is only likely to make his jam-packed fixture schedule even more congested.Along with the latest five City players to test positive, Walker.