Huddersfield Town's Oliver Norwood knows Northern Ireland fans will be pumping up the volume at Windsor Park tonight.

And the Huddersfield Town midfielder says that could be a key factor as Michael O’Neill’s men try to beat Portugal in their latest World Cup qualifier.

The Irish were victorious over Russia in Belfast last month, when Norwood’s Town teammate Martin Paterson headed home to clinch a 1-0 win.

And midfielder Norwood , hoping for an 11th cap, says the supporters really played their part at the tight venue which is home to Linfield, of Northern Ireland’s Premiership.

“There have been improvements made, but in international terms, it’s not that well developed,” he said.

“I think it’s a bit of a shock to the system for some opposing players, and when the fans start their noise, it must be even less appealing to them.

“We call them the GAWA (green and white army) and they are a loyal and passionate bunch who love their football and really get behind the team.”

Norwood was a key man as Northern Ireland fought out a battling 1-1 draw with tonight’s opponents in Porto last October (he is pictured, inset left, celebrating with scorer Niall McGinn).

And while Northern Ireland have virtually no chance of making the 2014 World Cup finals in Brazil, he says it’s crucial they build on that win over Russia.

“We all felt recent performances merit a result like we achieved last time, and we want to keep that momentum going,” he said.

Tonight’s clash brings Norwood’s former Manchester United teammate Cristiano Ronaldo to the province.

But Paterson, hoping to hold off competition from Palermo’s Kyle Lafferty to earn a 17th cap, says there are other players to worry about as well as the Real Madrid galactico.

O’Neill has defensive worries, with Aaron Hughes and Ryan McGivern both ruled out of tonight’s game and next Tuesday’s in Luxembourg (Bradford City’s Rory McArdle has been called into the squad).

And Paterson said: “Whoever plays tonight has to take a part in the defensive operation.

“We are up against some quality players – Ronaldo is just one of them.

“But we can also take some confidence into the game after the way we played against Russia.

“Our performances prior to that game had been good, but we maybe weren’t getting that rub of the green that is important.”