Michael O'Neill calms injury fears over Craig Cathcart and Kyle Lafferty

Michael O'Neill was able to allay injury fears over Craig Cathcart and Kyle Lafferty after the pair came off in a 0-0 draw with Slovakia that extended Northern Ireland's unbeaten run to 12 games.

In a contest where the hosts did not hold back despite now heading for Euro 2016 along with the Northern Irish, defender Cathcart took a knee to the back and striker Lafferty felt tightness in his calf, prompting O'Neill to bring both off.

However, neither problem is considered serious eight days ahead of their Euro 2016 opener with Poland, as O'Neill's men kept their impressive streak going in a contest where Aaron Hughes won his 100th cap.

"They're both fine; it was precautionary," O'Neill said. "Cathcart got a bad challenge, I thought. Obviously it was let go, like many.

"Kyle just had a little bit of a tight calf from a kick. We had planned to take off Kyle on 60-65 minutes. He wanted to stay on but there was no sense in it, and the same with Craig. If it was the Poland game in that situation and we needed them, they wouldn't have come off."

Slovakia's no-holds barred approach was surprising given both teams would have wanted to advance to France without any injury concerns.

And O'Neill, whose side face Poland, Ukraine and Germany in Group C, was disappointed that Romanian referee Marian Radu Petrescu failed to discipline a number of strong challenges.

"They're playing at home, the stadium's full and off the back of (the 3-1 win in) Germany, I'm sure they wanted to give the supporters a send-off and win the game," O'Neill added.

"I felt that some of the challenges under normal circumstances would have been punished with a yellow card but weren't. I thought the referee was lenient in favour of the home side at times. That's understandable."

That Slovakian approach did pave the way for Hughes to join Pat Jennings in his country's century club half an hour into the game.

There was no ceremony or celebration as he dashed in to defend a corner and O'Neill was delighted that a 36-year-old player used sparingly by club side Melbourne City last term showed he can still cut it on the international stage.

"It's fitting that Aaron is the first outfield player to gain 100 caps," he said.

"He didn't want it given to him and it certainly wasn't given to him tonight. He had to go on in difficult circumstances. My plan was to introduce him at some point in the game and I was actually delighted that I did put him on in the situation we did.

"It's important that we know he's still ready and he certainly showed that. He's not played a lot of football in Australia this year but what he has done, his focus has been to be ready for the finals.

"You see the reaction of the players in the dressing room with him, what it means for a player like Aaron Hughes to be part of this squad and to reach 100 caps."