Robbie Keane looks to be out of Ireland's Carling Nations Cup opener against Wales after picking up a calf injury in West Ham's 1-0 defeat to Birmingham.
Keane, who scored on his Hammers debut at Blackpool on Wednesday, had to come off with 15 minutes of Sunday's match at Upton Park remaining after feeling his calf tighten.
West Ham boss Avram Grant said that he believes the 30-year-old is out of Tuesday's game in Dublin and could miss next weekend's crucial match at West Brom.
Grant said: "Robbie Keane is injured. His calf has tightened.
"We will have to wait and see. I hope he will be fit for next weekend but he will not be fit for the international."
Celtic's Anthony Stokes was placed on standby for a call-up when Giovanni Trapattoni named his squad last week and could replace Keane if he is pulled out.
Bristol City striker Andy Keogh had to be drafted into the squad on Saturday after Newcastle striker Leon Best was injured in his side's remarkable 4-4 draw with Arsenal.