Kevin Doyle and Marc Wilson have pulled out of the Republic of Ireland squad to face Serbia on Wednesday.
Wolves striker Doyle has a bruised leg and Stoke defender Wilson a virus to further deplete a squad already missing experienced quartet Robbie Keane, Richard Dunne, Damien Duff and Shay Given.
Wilson looked set to play a role in Belgrade after sorting out his differences with manager Giovanni Trapattoni earlier this year.
However, he will miss out and Ipswich's Damien Delaney has been called up as defensive cover for the first game after Ireland's dismal performance at Euro 2012.
There are other injury doubts to concern the Italian, as Wolves left-back Stephen Ward and Keith Treacy of Burnley are struggling with knocks.
Sunderland's James McClean and Leeds midfielder Paul Green also missed Sunday's training session in Dublin but will join up with the squad later.