Johan Djourou admits it would be a "disaster" if Arsenal failed to reach the last 16 of the Champions League, but remains confident the Gunners can deliver.
Arsene Wenger was left fuming after his much-changed team were denied a stonewall penalty by Hungarian referee Viktor Kassai in the impressive Estadio Municipal, carved out of the Monte Castro quarry rockface.
Braga then capitalised when Emmanuel Eboue was off the pitch receiving treatment for a knee injury to net two late breakaway goals from Brazilian forward Matheus.
The 2-0 defeat means Arsenal - set to be without captain Cesc Fabregas for a couple of weeks after he limped off with a fresh hamstring problem last night - have lost successive European ties after opening their Group H campaign in blistering fashion with a 6-0 romp over Braga in London.
Indeed, should the Barclays Premier League club - still smarting from the painful loss against arch-rivals Tottenham - fail to beat whipping boys Partizan Belgrade at Emirates Stadium on December 8, then Arsenal could yet even drop down into the Europa League.
However, Djourou, one of seven changes to the starting XI by Wenger, insisted the Gunners can still be confident.
"If we didn't qualify, it would be a disaster," the Swiss centre-back admitted, "but we shouldn't think we are not going to qualify. We have to think positively.
"This defeat was a shock for everyone and we need to bounce back. "We have the players to do it, it is just how much we want it - and we do want to win a trophy."
Wenger lambasted Braga's negative tactics, with the Portuguese side, struggling in their domestic league, giving away 65% of possession, though Arsenal were unable to utilise it.
However, the only statistic which really mattered was their two goals from the three shots on target. The Gunners managed just one.
"When you have so much possession, the game should have been done," Djourou said.
"Theirs were silly goals, we should have avoided them."
Despite being ranked in the top eight by UEFA, Arsenal - Champions League finalists in 2006 - have a less than impressive away record, the 3-1 victory in Belgrade on September 28 only their fourth from the last 14 ties.
Nevertheless, Arsenal have still reached the quarter-finals or better in the past three seasons and have not failed to progress to the knockout stages in a decade.
With Fabregas set to be sidelined for a couple of weeks, Denilson could find himself with a run in the side.
The young Brazilian apologised to the travelling Gunners fans for another below-par European away performance.
"It is very disappointing and we are very sad about it. For the fans, I am very sorry for this match and the last game [Tottenham] as well," Denilson told Arsenal TV Online:
"But now we have to focus on the next match [at Aston Villa], and we have to keep going to win the trophies this season, because this is very important for us.
"In the Champions League, we have one more game against Partizan at home and we can be strong because the three points are very important.
"If we win, then we are in a good position."
Jack Wilshere had returned to the team after a back problem. The England midfielder also expressed the players' disappointment.
Wilshere said on his personal Twitter account: "Would like to apologise to all the supporters, especially the ones that travelled, for the result last night. Still cant get my head around how we can lose this game after dominating for so long."
Wenger admitted his gamble on Fabregas had backfired last night, having expressed concerns about the overuse of his talisman ahead of the fixture.
The World Cup winner had already missed five weeks of the season because of a troublesome hamstring, with a similar issue now having cropped up on the midfielder's other leg.
Fabregas will play no part in Saturday's trip to Aston Villa, or the Carling Cup quarter-final against Wigan next week and could also be in a race to be fit for the clash with Manchester United at Old Trafford on December 13.
Eboue, meanwhile, will also be assessed, with medial knee ligament damage the early prognosis following a late challenge by Matheus which went unpunished.
On a positive note, however, Wenger will have been boosted by the return to action of Wales midfielder Aaron Ramsey in the reserves following his broken leg.Reuse content