Portugal boss Fernando Santos is worried by the number of goals his side have conceded in recent games.
The Selecao claimed a 3-1 win over nine-man Qatar in Saturday's friendly to make it back-to-back victories since exiting Euro 2020 to Belgium at the last-16 stage.
Santos made 11 changes on the back of the late 2-1 victory over Republic of Ireland and Portugal took time to get going against World Cup 2022 hosts Qatar.
However, quickfire goals from Andre Silva and debutant Otavio put Portugal in control at half-time, at which point Qatar were a player short after Meshaal Barsham was dismissed.
Portugal switched off in the second period and gave their opponents a route back into the game when Abdelkarim Hassan headed in unmarked.
Bruno Fernandes converted a penalty late on to seal the win for the 2016 European champions, but Santos was not entirely pleased with his much-changed side's performance.
"In the first 15 minutes, we were good in terms of our defensive organisation," he said at his post-match news conference.
"When Qatar were looking to attack from behind, we were good. We never let Qatar create, we stole a lot of balls and with clear situations of being able to score on the counter.
"But in ball circulation, we were very slow and a lot of passes went astray, which allowed Qatar to create two or three opportunities on the counter-attack.
"They have very fast players up front. In the first 15 minutes, in terms of scoring opportunities, we ended up being equal.
"After those 15 minutes, the possibility for them to counter-attack ended, the team began to circulate in a different way, creating situations with lots of security.
"We pressed very well, made it 2-0 and it could have been more.
"We were still good in the first 10 minutes of the second half. But we disconnected a little and let the opponent pick up the ball and they scored, meaning we couldn't relax."
Portugal, who required a couple of late headers from Cristiano Ronaldo to overcome Republic of Ireland on Wednesday, have now conceded nine goals in their last five matches.
That follows on from a run of three games in a row without conceding earlier this year.
"A team that concedes nine goals in five games is worrying," Santos added. "There are things we have always done very well and one of them is defensive set-pieces.
"It was very rare for us to concede goals like that, but now we do. I've already alerted the players to that. Just this morning we spent time working on set-pieces."
Brazilian-born Otavio obtained Portuguese citizenship in March and marked his first appearance for the Selecao with a goal.
He scored from one of his two shots on target and also played a joint-high three key passes, which was matched by Fernandes despite the midfielder only playing 30 minutes.
Asked what he made of Otavio's display, Santos said: "He was part of the group of players that did well for 30 minutes."
Portugal switch focus back to their World Cup qualifying Group A campaign with a trip to Azerbaijan on Tuesday.