Ireland's presence had initially been in doubt when he was taken to hospital on Wednesday night after complaining of dizziness during the Carling Cup win over Fulham. The midfielder was subsequently released, with his symptoms diagnosed as nothing more serious than extreme tiredness.
However, his hopes of facing Gianfranco Zola's men seem to have collapsed amid reports Ireland contracted a virus late last week which saw him ordered home from the City training ground.
Gareth Barry had suffered from the same problem, but his recovery has apparently been quicker and he should face the Hammers as City look to move back into the top four.
If, as expected, Ireland does miss out, manager Mark Hughes will face a selection dilemma as he does not have an obvious like-for-like replacement.
Should Micah Richards recover from a shoulder problem, Pablo Zabaleta could move into midfield alongside Barry and Nigel de Jong.
Martin Petrov is another alternative in a more orthodox 4-4-2 formation, while there is also a chance £17million forward Roque Santa Cruz could be handed a starting berth for his debut after being sidelined since his summer move from Blackburn due to a knee operation.