Northern Ireland manager Michael O'Neill has added Kyle Lafferty and Mark Sykes to his squad for the games against Luxembourg and Germany.
The pair are due to link up with the rest of the group in Belfast later on Wednesday after injuries to Michael Smith and Jordan Jones forced the manager to act.
Lafferty, Northern Ireland's second top scorer, was initially left out of the squad following his recent move to Norwegian club Sarpsborg.
He becomes the second striker to be added to the squad since it was initially announced last week, with Shayne Lavery already brought up from the under-21s following an injury to Paul Smyth.
Oxford defender Sykes is yet to earn a first senior cap but was part of O'Neill's squad in May. He has 11 caps for the under-21s.
"I am always very proud to represent my country and I'm looking forward to it," the 22-year-old said on the Oxford website.
Northern Ireland face Luxembourg in a friendly on Thursday night before a Euro 2020 qualifier against Germany on Monday night.
