Angry home fans greeted the final whistle of Saturday's listless outing in Lisbon with boos and whistles, the result marking the second game in succession that Portugal had failed to find the net following February's stalemate with Poland.
The barren run has raised question marks over Portugal's chances heading to Poland and Ukraine, particularly given the strength of their group-stage opponents - Germany, Holland and Denmark.
Bento's side contest their final warm-up against Turkey tomorrow [Saturday], and the coach is confident his players will prove their worth.
"There were no problems with players' attitude and that makes us calm," Bento told reporters. "We will try harder tomorrow [Saturday], knowing that Turkey will play differently.
"We want to improve every game, we want to win.
"I am an optimist by nature but there is concern for the game with Macedonia.
"Tomorrow we will have a different game, we want to win and therefore we have to score."
Bento has meanwhile rubbished claims that Portugal's Euro hopes rest solely with Cristiano Ronaldo, who is coming off the back of a stellar title-winning season with Real Madrid.
"We're not putting pressure on him to solve all our problems, but we hope he'll help us to solve some of them," Bento said.
"We want a team that plays well. We don't want Ronaldo to have to do everything."
England manager Roy Hodgson has played down fears about the fitness of Scott Parker ahead of tomorrow's [Saturday] friendly with Belgium at Wembley.
Having already seen Frank Lampard and Gareth Barry ruled out of Euro 2012 by injury, England can ill afford to lose another midfielder ahead of their Group D opener against France on June 11, but Hodgson has eased concerns about Parker, who has been battling an Achilles injury.
"I don't have any concern about Scott other than the obvious one when he came to join us not having played in Tottenham's last few matches," said Hodgson.
"That was going to be a factor but we also knew that we had lots of training time.
"He has taken part in every session and is getting fitter by the day."
Holland midfielder Wesley Sneijder is in bullish mood ahead of his side's warm-up game against Northern Ireland at the Amsterdam ArenA.
Bert van Marwijk's men are eyeing back-to-back wins after bouncing back from a 2-1 loss to Bulgaria in their first warm-up game by defeating Slovakia 2-0.
The Oranje are one of the favourites for the European Championship after reaching the World Cup final in 2010, where they were narrowly beaten 1-0 by Spain.
Sneijder expects Spain - also the reigning European champions - to remain the team to beat in Poland and Ukraine, and also believes the Dutch will again emerge as the team they must overcome in the final.
"There haven't been many changes in the Spain squad. All their players are about 25, 26 years old. I think that they have the best team and will make it to the final, and so will we," Sneijder told NUsport.
Holland open their Group B account on June 9 against Denmark, who will be eager to recover from their 3-1 defeat to Brazil last weekend when they continue their preparations with a tune-up against Australia in Copenhagen.
Croatia coach Slaven Bilic believes his side's match against Norway in Oslo will provide his players with the ideal preparation for their first Group C game against the Republic of Ireland on June 10.
"We couldn't have a better warm-up for the opening match against Ireland," Bilic told reporters.
"Norway are something like Ireland, they're two teams very similar in their style of play and team ability. The match in Oslo will show us where we are a week before our first match. I believe I will get my answers tomorrow [Saturday]."
Elsewhere tomorrow [Saturday], co-hosts Poland are in action against Andorra, while on Sunday Spain continue their build-up to the defence of their title with a match against China in Seville.