Michael O'Neill admits Kyle Lafferty's situation at Norwich City has given him a conundrum, but praised Northern Ireland's talisman for his late brace against San Marino.

The man who scored seven times in the previous qualifying campaign arrived with 18 minutes to go at Windsor Park, with his country only 1-0 up, and he scored twice and set up another for Jamie Ward as O'Neill's team ran out 4-0 winners in their World Cup qualifier.

Lafferty is well down the striker pecking order at Carrow Road, meaning O'Neill has a player whose depleted fitness levels were evident when he started and faded in last month's 0-0 draw with the Czech Republic.

'My situation with Kyle's fitness is simple: do I play him for 50 minutes and take him off because he's not played many minutes over the past year? Or do we get more out of him bringing him into the game later on?' O'Neill said.

'The last 20 minutes, maybe the game's stretched a bit, the opposition are tired and there's opportunities there for him.

'He took his chance when he came on. I think he understands the situation. It's very difficult to walk into international football and just play if you've not played for your club.

'He's not starting because he's not been played. We've had a situation in the sense Kyle's played 45 minutes of football in a month.

'Going back to the Czech Republic, we ran out of gas in the second half because we had too many players that hadn't played too many minutes for their club.

'When I look at Kyle's situation, it's about where we can maximise his use to the team and (Saturday night) was the best example of doing that.

'He came in when it was stretched, we needed that second goal. He came on and did it fairly quickly.

'(On Saturday night) he proved what a huge asset he is to the team. We need him more match-ready than he is and I think he knows that.'

The tall striker came on with Steven Davis' penalty the only contribution to the scoresheet, but the home side were eventually able to claim a comprehensive victory having amassed over 30 shots on Aldo Simoncini's goal in the first international hosted at their fully refurbished stadium.