Hull City midfielder David Meyler has been ruled out of the Republic of Ireland's Euro 2016 play-off against Bosnia-Herzegovina with a knee injury.
The 26-year-old picked up the injury in a collision with team-mate Marc Wilson in training ahead of the first leg.
Meyler is expected to be out of action for up to eight weeks after an MRI scan revealed that he had suffered a grade 2 tear of his right knee medial ligament.
Shane Long will miss Friday's first leg to get treatment on a foot injury.
Striker Long, who hit the winner in last month's shock victory over Germany, has remained with his club Southampton, but has not been ruled out of Monday's return leg in Dublin.
Charlton keeper Stephen Henderson has been called up after Keiren Westwood and Rob Elliot were both ruled out.
Newcastle's Elliot has been forced to pull out because of a thigh injury while Sheffield Wednesday's Westwood misses out after a pre-existing ankle injury flared up in Republic training on Wednesday.
With veteran Shay Given also ruled out by injury, Darren Randolph is expected to start ahead of David Forde.
West Ham keeper Randolph played in the Republic's last two qualifiers, replacing Given against Germany and starting in the defeat by Poland.
With Long missing and Jonathan Walters suspended, Ipswich striker Daryl Murphy looks likely to start in Zenica.
After hitting the winning against Germany, Long sustained a foot injury in the defeat by Poland three days later.
Long has not played since and recently underwent an injection in his foot.
Reading defender Paul McShane is absent through injury while manager Martin O'Neill is waiting for news on whether John O'Shea will be fit for Monday's second leg in Dublin.
O'Shea, like Stoke striker Walters, is suspended for the first leg but the Sunderland defender is also a doubt for the Aviva Stadium contest because of a hamstring injury.
With O'Shea suspended, Aston Villa's Ciaran Clark and Stoke's Marc Wilson appear the candidates to be drafted into the Republic defence.
Midfielder Alan Judge, who stayed at Brentford this week to continue his rehabilitation from a hamstring injury, has joined up with the Irish squad
Mehmed Baždarević, Bosnia and Herzegovina coach
We will not change our game plan because of their problems with injured goalkeepers. Ireland are without some of their very good players but they do have the capacity to replace them. After training, we will decide if we will play in our standard 4-3-3 formation, or make some changes.
Martin O'Neill, Republic of Ireland manager
Our missing players have been the talk of the week, even before we gathered as we knew we were missing players due to suspension. This all plays a part but it's how you cope with it and in two weeks' time, no one will remember who was injured or suspended. We have talked about the players who can't make it here but we have to deal with the people we have here and to be ready for the challenge, it's a big challenge.