Villas-Boas has conceded that the Gunners possess a potent threat to their hopes of a return to Europe's elite club competition, primarily because they have finished the season in form on a regular basis in the past.
He told The Mirror: "The reality is that Arsenal feel their belief is because they finish seasons very strongly and that belief helps them.
"We don't look at ghosts in the past. We try to do our job properly. We want to win games. It's nothing to do with our tiredness. It (today) was an opportunity for other people to step up.
"It's not just Gareth we're missing, it's Aaron Lennon, Jermain Defoe and Sandro, who was the best recoverer of all in the Premier League when he was injured. I think we've seen players stepping up a level today: Gylfi Sigurdsson, Emmanuel Adebayor, Tom Carroll and Tom Huddlestone all doing ever so well."
Spurs are back in Europa League action on Thursday in the second leg of their quarter-final tie with FC Basel.