Roberto Martinez's side will open their Euro 2024 campaign against Czech Republic on June 18, while Republic of Ireland will be back in competitive action in the UEFA Nations League at the start of September.
Match preview
Portugal lost for the second time in three matches on Saturday evening, with Croatia running out 2-1 winners in their friendly encounter in Oeiras, and Martinez's team will now be bidding to bounce back in their final game before Euro 2024.
The 2016 European Champions levelled Saturday's friendly through Diogo Jota after Luka Modric had made the breakthrough from the penalty spot, but Ante Budimir won it for the visitors in the 56th minute.
Portugal have now been beaten in two of their last friendlies, also losing 2-0 to Slovenia at the end of March, and the national side will now looking to enter the European Championship off the back of a positive result.
Martinez's side will open their Group F campaign against Czech Republic on June 18, before taking on Turkey and Georgia in their final two group matches, and it would be a surprise if they were unable to navigate their way into the knockout round of the competition.
Portugal won Euro 2016, but they were knocked out in the round of 16 at Euro 2020 before making the quarter-finals of the 2022 World Cup in Qatar.
Republic of Ireland will not be present at this summer's European Championship, having finished fourth in their qualification section, picking up only six points from eight matches during a difficult campaign.
John O'Shea remains in charge of the national team on an interim basis, and the former Manchester United defender will again be at the helm for this glamour friendly with Portugal.
Republic of Ireland have only actually qualified for the finals of three European Championships, with their last appearance at the competition coming eight years ago, when they reached the round of 16 in France.
The visitors will enter this match off the back of a 2-1 win over Hungary in a friendly on June 4, which proved to be their first success in five matches, and they will be back in competitive action in the 2024-25 UEFA Nations League against England at the start of September.
Republic of Ireland have lost eight of their previous 15 matches with Portugal, but the points were shared in a goalless draw when they last locked horns in a World Cup qualifier back in November 2021.
Portugal friendly form:
Portugal form (all competitions):
W
W
W
L
W
L
Republic of Ireland friendly form:
Republic of Ireland form (all competitions):
W
L
D
D
L
W
Team News
Cristiano Ronaldo was an unused substitute for Portugal's 2-1 defeat to Croatia last time out, but the 39-year-old is expected to come into the starting side for the contest with Republic of Ireland.
Head coach Martinez will make changes to the side that started on Saturday, with Joao Cancelo, Jota and Antonio Silva likely to come into the XI alongside Ronaldo.
Bruno Fernandes, Joao Palhinha and Vitinha should retain their spots in midfield, but Matheus Nunes and Joao Neves should receive action at some stage of the contest.
Rafael Leao is also pushing to start the national team's Euro 2024 opener, and the AC Milan forward could potentially another 45 minutes of action.
As for Republic of Ireland, interim manager O'Shea could name the same side that took to the field for the first whistle of the success over Hungary last time out.
Adam Idah netted his fourth international goal in the 2-1 win, but Troy Parrott is also pushing to start, as his goal off the bench against Hungary proved to be his fifth strike for his country.
Seamus Coleman should again captain the team from the middle of the defence, while Robbie Brady and Shane Duffy are also set to be among the starters for the away side on Tuesday night.
Portugal possible starting lineup:
Costa; Cancelo, A Silva, Dias, Dalot; Fernandes, Palhinha, Vitinha; Bernardo, Ronaldo, Jota
Republic of Ireland possible starting lineup:
Kelleher; Coleman, Duffy, D O'Shea; Doherty, Smallbone, Cullen, Brady; Azaz, Idah, Szmodics
We say: Portugal 2-0 Republic of Ireland
Martinez will not have been overly concerned by his team's performance against Croatia, but he will not want to enter Euro 2024 off the back of another disappointing result. Republic of Ireland are capable of making this a tricky match, but we are expecting the hosts to navigate their way to a comfortable win.