Seamus Coleman insists the Republic of Ireland must concentrate on hurting Portugal rather than trying to ruin Cristiano Ronaldo's big night as they head into World Cup qualifier battle in Faro.

Ireland will run out at the Estadio Algarve desperate to open their Group A account at the third time of asking, but knowing they face one of the biggest threats in international football as 36-year-old Ronaldo bids to celebrate his return to Manchester United by eclipsing Iran striker Ali Daei's record of 109 international goals.

However, skipper Coleman said: "Listen, it's not a case of ruining any parties or anything. We've got to focus on ourselves.

"Everyone in the room and everyone in the world knows how important and how amazing Cristiano Ronaldo has been over the last 15 years. It's incredible, really, the numbers that he's provided over that course of time.

"As a group, we've got to focus on what our plan is tomorrow and how we can stop them playing – they have a few players we have to keep an eye on – and what we can bring to the game.

"But listen, it's going to be tough. He's one of the best players who's ever played the game and we're looking forward to getting out there and playing against him.

"But ultimately, we will have our own plan and will try to take that to them as well."

Manager Stephen Kenny too, needs no reminding of the threat posed by the former Real Madrid and Juventus superstar, as well as his team-mates.

Kenny said: "Without doubt, he's an outstanding talent and has been for nearly two decades now, really. It's been such a long period of time since he first emerged.

"They've got a lot of good players all over the park and – from our point of view – it's a great game for us.

"It's an important World Cup qualifier and the players, we feel, we've got a lot of potential in our team.

"We've blooded a lot of players. We've given 11 players their competitive debut, we've given other players some friendly games. We're looking to see even more progress.

"We had a good June window and we want to carry that into this window starting with the game against Portugal, and we're looking forward to the game."

Former European champions Portugal currently sit at the top of the group along with Serbia having taken seven points from their opening three fixtures, and few would bet against them adding to their tally on Wednesday evening.

However Kenny, who saw Fernando Santos' side lose 4-2 to Germany and draw 2-2 with France before exiting the Euro 2020 finals in the last 16 at the hands of Belgium, is adamant all-out defence is not the answer.

He said: "We have to carry an attacking threat, we can't afford to defend for 90 minutes. It's not the way we're set up to do that, it's not our intention.

"We have to carry an attacking threat. Portugal have too much quality to sit back for 90 minutes, it's not workable.

"We have to have belief in ourselves to carry an attacking threat, and that's certainly our ambition."