Northern Ireland will be without Alex Bruce and Grant McCann for their World Cup qualifier away to Portugal on Tuesday.
Hull defender Bruce was due to make his international debut for his new nation after transferring his allegiance from the Republic of Ireland, but a groin strain has forced him to return home.
McCann has sustained a knee injury meaning he will also miss the meeting with the second-placed Portuguese in Group F.
Manager Michael O’Neill was already without the services of West Bromwich Albion captain Chris Brunt and Derby’s Jamie Ward through injury.
Bruce’s Hull team-mate Joe Dudgeon, Newcastle’s Shane Ferguson, Burnley’s Martin Paterson and Hibernian’s James McPake have also all pulled out of the squad.
O’Neill has already drafted in Bradford’s Rory McArdle, Burnley’s Daniel Lafferty and Watford’s Lee Hodson, but will not be calling up additional replacements for Bruce and McCann.