Northern Ireland manager Michael O'Neill says he is "disappointed" Kyle Lafferty has "ruled himself out" of the Nations League games against Austria and Bosnia-Herzegovina.

O'Neill said the Rangers striker, 31, contacted him on Sunday night to inform him of his surprise absence.

"I am disappointed he has ruled himself out of the two games," said O'Neill.

"Our focus is the players who are with us and I will address this situation after the international period."

Northern Ireland face Austria in Vienna on Friday and Bosnia in Sarajevo on Monday, needing to pick up points after the opening home defeat by the Bosnians last month.

Lafferty started Northern Ireland's Nations League opener to earn his 68th cap and is one of the most experienced members of O'Neill's squad.

But O'Neill said Lafferty - who was benched for Rangers' match with his former club Hearts at the weekend - had taken the decision himself not to travel.