Linfield will be without striker Shayne Lavery and winger Joel Cooper for Monday's second leg of the inaugural Champions Cup away to Dundalk.
Blues manager David Healy revealed that Cooper needed surgery for a nose injury he suffered in their recent Irish Premiership win over Carrick Rangers.
Lavery, who scored in Friday's 1-1 draw in the first leg at Windsor Park, will be on Northern Ireland duty.
"Joel won't be available," Healy said in an interview tweeted by Linfield.
"He is having a slight operation on his nose to help with his breathing. He took a heavy bang against Carrick which wasn't penalised, which was disappointing, but that happens in football.
"I will asses the squad. The pleasing thing is that Josh Robinson is in and around being fit again, Chris Casement came through 60-odd minutes in the Swifts while Mark Haughey is nearing a return."
Looking ahead to Monday night's match at Oriel Park, Healy said he is fully aware of what to expect from the Premier Division champions.
"I've been down there numerous times in a watching brief and it's going to be a hugely difficult task," he said.
"It's a tight ground and there will be a ferocious atmosphere - the away teams always get a hostile reception but hopefully our players can thrive on that.
"If we do our jobs and capitalise on any opportunities we make then we can come back up the road with an all-Ireland trophy."