Owen Garvan, Billy Clarke and Tommy Smith have all be forced out of international squads by injury. Garvan and Clarke were due to play for the Irish U21s at home to Bulgaria on Tuesday, while Smith was set for action with the England U18s against Ghana at Gillingham the same night.
Physio Matt Byard told the club site that Garvan and Clarke are both doubts ahead of the Cardiff game a week on Saturday: "Owen's calf is still a problem, so unfortunately he has had to be pulled out of the [Bulgaria] game next week as well.
"It's touch and go whether he will be fit against Cardiff. He will continue to be monitored and we will see how he progresses.
"We have also pulled Billy out of the squad. He picked up a thigh injury in training this week and will be staying behind for treatment. Like Owen, it's a question of looking at him later next week and taking it from there."
Central defender Smith picked up a knee injury during the behind-closed-doors reserves game with Spurs earlier in the week.
Town's international contingent is now reduced to Shane Supple, with the Irish U21s for tonight's game in Montenegro and on Tuesday against Bulgaria, Chris Casement, Northern Irish U21s taking on Luxembourg tonight and Moldova on Tuesday, Alex Bruce, with the Irish senior side playing Wales in Cardiff on Saturday, and Jon Walters, named in the Irish B side playing Scotland on Tuesday.