Nottingham Forest midfielder Sammy Clingan is out of Northern Ireland's Euro 2008 qualifiers later this month after breaking an ankle.
Sammy Clingan has been a key player for Northern Ireland
The 23-year-old suffered the injury in Forest's 5-1 league victory over Huddersfield on Saturday.
Northern Ireland are away to minnows Liechtenstein on 24 March and host Group F leaders Sweden four days later.
Clingan's absence is a major blow for Northern Ireland after his recent impressive international displays.
The former Northern Ireland U21 captain moved to League One side Forest from Wolves for a nominal fee in January last year.
Northern Ireland manager Lawrie Sanchez handed Clingan his senior debut in a friendly against Uruguay last May in New York.
He made an immediate impact and is now a regular in the heart of Northern Ireland's midfield.
Sanchez's side sit third in Group F after four games, five points behind unbeaten Sweden.