Chelsea travel to Manchester to face a City side that have endured a difficult start to the league campaign.
Sunday’s opponents have been hampered with injuries and only have one victory from five league games, but Hayes expects a tough encounter this weekend.
She said: ‘Everybody has got full-time professional players and they’ve lost players, but they’ve got great players that can come into the team. They showed that in their 5-1 win against Everton that they are full of quality.
‘They’ve just been a bit unfortunate sometimes. In the games I’ve watched, I’ve seen them dominate and just not take their chances. I’ve listened to Gareth’s interview and he’s been spot on. Sometimes when you get into a bad place, sometimes the confidence gets affected and then things just happen.
‘They haven’t been poor, they’ve been a little unfortunate and the injuries haven’t helped their situation, but they are a really good team. They’ve shown that even with Jill Scott coming into the team. What a brilliant player she has been for that club and I don’t underestimate them. I’ve been in this job too long to ever do that.’