Sunderland defender John O'Shea did not train with the Republic of Ireland squad on Monday, raising concerns about his fitness ahead of Euro 2012.
The 31-year-old is still recovering from an ankle knock picked up on the final weekend of the season, and is likely to miss Saturday's friendly against Bosnia-Herzegovina.
O'Shea is expected to be fit for his country's opening match with Croatia on June 10, according to Sky Sports News, but doubts remain about his level of fitness.
O'Shea has 75 international caps to his name.