"It's just a case of how he can protect the elbow and manage to play," O'Neill said. "We'll see how things develop for him this week and at Norwich as well.

"We have until next Thursday so there's a little bit longer in terms of a healing process. Having spoken to him in the week he's optimistic and we have to be as well because he's been such a significant player for us and a very difficult player for us to replace if he's not available."

O'Neill has called uncapped St Johnstone winger Matthew Kennedy into his squad, the only new face in the group.

The 24-year-old was born in Belfast to Scottish parents, and raised in Ayrshire, coming through the ranks at Kilmarnock before moving to Everton, with subsequent loan spells at Tranmere, MK Dons, Hibs and Cardiff.

His move to St Johnstone last year has seen him blossom and catch the eye of O'Neill.

"He's really come to the fore at St Johnstone," O'Neill said. "He was very good last season. He was maybe not at the top of his game at the start of his season with St Johnstone having a difficult time but he's an exciting player, a creative player."

"His preferred position is on the left but he just gives us another option in terms of an attacking player in the final third of the pitch and it's nice to have him in."

Hearts full-back Michael Smith is back in the squad after injury, while Linfield striker Shayne Lavery, Motherwell midfielder Liam Donnelly and Cardiff defender Ciaron Brown all retain their places after being called up for the September fixtures.

Northern Ireland sit in second place in Group C, level on 12 points with leaders Germany after losing 2-0 to them in Belfast last month.

That was the first setback for O'Neill's men in the group after they won their first four fixtures, but they still face a very difficult path to qualification, realistically needing to pick up points against the Dutch home and away after Holland's victory over Germany last month.

"Germany losing to the Netherlands was probably not the result we wanted, it sways the head-to-head in favour of the Netherlands in terms of our two games against them," O'Neill said.

"We have to find a way to get four points, whether that's a draw away from home to set up a massive game for ourselves in Belfast or try to win the game in Rotterdam.

"Those are the challenges we face."