Aaron Hughes expects Cristiano Ronaldo to be at his best when Northern Ireland face Portugal on Tuesday night.
The Real Madrid star is set to win his 100th cap in the World Cup qualifier at Porto's Dragao Stadium and will be eyeing goals against a leaky Northern Ireland defence.
Fulham centre-back Hughes will be one of those hoping to stop the former Manchester United man but knows it'll be tough against a player who has scored 14 times in 11 club matches this season.
"I have played a handful of times against him but maybe he has gone another level since his days in the Premier League, and maybe he can go further," said Hughes.
"He has gone and become just as successful in Spain and maybe there's more to come from him. I don't think he has peaked, believe it or not. He is still going and appears to be getting better.
"Lionel Messi and Ronaldo are the two who stand out as the best two in the world.
"He is one of those players who makes you feel as if he has been around forever and playing forever, so the fact he's reaching 100 caps already doesn't surprise me, even at 27.
"He is more than worthy of that, but that - whether it is his 100th or his 10th - what makes players great like that is they play like that every time and rarely have an off-night.
"The best players play at that level every single night whether it is the first game of the season, a windy night in November or the Champions League, it is just their way.
"It's not just technical ability, it is the attitude to reproduce that every single night. You look at sport in general, the likes of Michael Jordan, they are the best."