Hearts full-back Michael Smith out of Northern Ireland's double header

Hearts defender Michael Smith looks on during Saturday's 2-2 draw with Hamilton

Manager Michael O'Neill described Smith's absence as "a blow" after the right-back was declared unfit for Thursday's friendly with Luxembourg and Monday's European Championship qualifier against Germany.

He strained a hamstring playing for Hearts against Celtic ten days ago and missed Saturday's draw with Hamilton as a result. That left him doubtful for Northern Ireland's double header.

O'Neill named the 31-year-old in the squad last week but he has been forced to withdraw.

"Michael Smith is not with us," said O’Neill. "Unfortunately, Michael’s hamstring injury means that he won’t be able to be fit for either game which is a blow."

Rangers winger Jordan Jones is also out after injuring himself in a tackle during Sunday's defeat by Celtic. Former Hearts forward Kyle Lafferty and Oxford United midfielder Mark Sykes have been added to the Northern Ireland squad.

"Jordan Jones isn’t with us. People will have seen the incident at the weekend so Jordan isn’t with us," said O'Neill.