He told the London Evening Standard: "This time last year, it would have been a very interesting game. It's a bit like us playing Manchester United before we sold our centre-forward, Robin van Persie, to them.
Adams also believes the Champions League is beyond Arsenal this season.
"I am not alone here - I think most of the Arsenal fans would agree with me. Strange things happen, like Chelsea winning with not the greatest team in the world, but they did have the whole team fighting to keep clean sheets.
"I think they will beat Montpellier but in recent years you just fear they cannot go away from home and do a professional job.
"The thing is, they have to do it for two or three years before they get that reputation back as a resilient side.
"They have sent out the wrong message piece by piece for seven years and it chips away at your credibility. Selling your best players is part of that."