Northern Ireland manager Michael O'Neill fears Cristiano Ronaldo will be on a "revenge" mission in Friday night's qualifier in Belfast – despite his side doing Portugal a favour last month.

Last month's 1-0 defeat of Portugal's main group rivals Russia – O'Neill's first win after ten matches and 20 months in charge – may have redressed the balance a little. But the Northern Ireland manager said: "Did we ruin Ronaldo's big night? Possibly. Perhaps there will be a little bit of revenge this week.

"He is an awesome player, but we did really well against him in Oporto. It was all down to good organisation and hard work and we'll require a similar type of performance at Windsor Park. He can test you in so many ways.

"People will look at his shooting or the way he goes past players, but he has fantastic heading ability and so many other qualities. If you give players like Ronaldo space, that's when they hurt you most, so we'll have to be careful in how we approach this game."

Portugal, who defeated Russia 1-0 at home in their last qualifier in June, top the pool by two points, but Fabio Capello's side have a game in hand. They host Luxembourg and Israel over the next week while the Belfast trip is Portugal's only fixture this month.

"It's a massive game for Portugal - they have to come here and win," said O'Neill, whose team are six points adrift of Russia in fourth. "Automatic qualification still rests in Russia's hands and they'll want to take that away from them, given the fact that they don't play each other again. Portugal know they cannot afford to drop any points against us."

Portugal coach Paulo Bento is bracing himself for a "very difficult" night in Belfast after Martin Paterson's header condemned Russia to Windsor Park defeat three weeks ago. "It is a warning, not only for the outcome but because it was a fair result. Russia did not create any clear goalscoring opportunities," Bento said. "They are a very intense squad both offensively and defensively and they are very aggressive with a direct style of football.

"We are depending on other results," Bento added. "Northern Ireland have taken points off us and Russia, so it will be very difficult, but we know we have to keep on track."

Northern Ireland are boosted by the return of a key trio: Manchester United FC defender Jonny Evans, West Bromwich Albion FC winger Chris Brunt and US Città di Palermo forward Kyle Lafferty, who all missed the Russia fixture.