Cristiano Ronaldo vowed to be a "good boy" when Portugal face the Republic of Ireland in World Cup qualifying, as he expects to get boos from the crowd at the Aviva Stadium.

Portugal will secure qualification for next year's tournament with a win in Dublin, while Ireland are currently third in Group F, one point off second place, with work to do to earn the play-off spot.

The Selecao won the reverse fixture 1-0 on home soil, with Ruben Neves' 91st-minute winner securing all three points after Ireland had put on a backs-to-the-wall defensive display.

Ronaldo celebrated Neves' goal in the face of Ireland defender Jake O'Brien and noted that he does not expect a warm welcome from the home fans when he steps out on Thursday.

"I really like the fans here. The support they give to the national team it's lovely. For me, it's a pleasure to come and play here again," Ronaldo said.

"Of course, it will be tough. I hope they don't boo me too much. I swear that I'm going to try to be a good boy.

"But of course, I do my job. I try to win the game and try to score to help my team. I'm sure that the game will be difficult."

Only two players have attempted more shots during UEFA World Cup qualifying than Ronaldo (26), who has five goals in four appearances, though he had a penalty saved by Caoimhin Kelleher in the reverse fixture.

The last time he featured at the Aviva Stadium, he had five shots without scoring in a goalless draw in November 2021.

Ronaldo announced earlier this week that the 2026 World Cup will be his last major international tournament before retirement.

The 40-year-old, who has scored 143 goals for Portugal in his career, is determined to add to his already impressive trophy haul but insists their push for the trophy in the United States, Canada and Mexico is about more than just him.

"A national team doesn't depend on one good player, but it helps to have good players who can make a difference, especially with goals," he added.

"It's always good for me to score goals. I want to play in this next World Cup, but we'll take it step by step."