Manuel Pellegrini wants to get West Ham's season back on course while at the same time doing his old club a favour.
West Ham host leaders Liverpool on Monday night desperate for a decent performance after three straight defeats.
Manchester City will be watching events at the London Stadium closely as they attempt to chase down the Reds, just as they did under Pellegrini in 2014 to claim the title.
"If we win I will be very happy for our club first, because we need a good performance against the leaders," said Hammers boss Pellegrini.
"After that if we can give a hand to Manchester City, it's not our problem, but of course I am a fan of Manchester City also."
However, Pellegrini feels Liverpool's exit from both domestic cups will still give them an edge in the title race even if they come unstuck in east London.
The Chilean insists Tottenham - knocked out of both cups last week - also cannot be discounted.
"It's more easy for the team that is involved in just two competitions compared to the team that is involved in four," he added.
"Tottenham? You should never think that a team four or five points behind you are not involved in the title. Of course they are.