Republic of Ireland captain Robbie Keane looks set to miss his country's Carling Nations Cup opener against Wales.
West Ham striker Keane limped out of his home debut against Birmingham with a calf injury.
Hammers boss Avram Grant, who was forced to substitute his new loan signing after 75 minutes, believes the 30-year-old is out of the Dublin clash.
But he is hopeful Keane could return for West Ham's crucial relegation battle 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."
If Keane does pull out of the squad then Ireland boss Giovanni Trapattoni is likely to call up Celtic's Anthony Stokes as his replacement.
But the skipper's absence would be another blow for the Italian after already losing Newcastle striker Leon Best and Portsmouth midfielder Liam Lawrence from his original squad.