The Gunners were beaten 2-1 by Chelsea on Sunday at Stamford Bridge as they slumped to their second straight Premier League defeat to leave them off the pace in the race for the Champions League spots.
The north Londoners play their game in hand when they host West Ham United at Emirates Stadium on Wednesday.
And despite residing in sixth place with 16 games left to play, the Arsenal captain is remaining upbeat about his side’s chances of finishing in the top four.
“It was really frustrating. We know we have the quality to beat Chelsea but it’s all about results,” Vermaelen told Arsenal’s website.
“We don’t have to look too far ahead. There’s still a long way to go. I’m still confident.
“You could see it [on Sunday] in the second half. I’m still confident we can get a good [position].”