Watford defender Craig Cathcart has been ruled out of Northern Ireland’s World Cup qualifiers against San Marino and the Czech Republic.
Cathcart, 28, sustained a knee injury in his club’s Premier League draw with Brighton on Saturday.
Hearts defender Michael Smith, who earned his only cap last year, has been called into the squad as a replacement.
Uncapped Leeds United goalkeeper Bailey Peacock-Farrell has also been added to the squad.
Cathcart’s absence is a blow to manager Michael O’Neill as experienced West Brom defender Gareth McAuley will miss both games because of a thigh injury.
Northern Ireland face San Marino away on Friday evening before the home qualifier against the Czech Republic on 4 September.
O’Neill’s side are second in Group C and on course for a play-off spot.
With four rounds of fixtures left, world champions Germany lead the table on a maximum 18 points with Northern Ireland five points off the place and the Czechs a further four points adrift in third spot.