Dembele became a big hit with Spurs fans for his excellent performances in midfield, but the Londoners have had to do without the Belgian for the last five games after he aggravated an old hip injury while on international duty.
Villas-Boas said last Thursday he feared the 25-year-old could have to go under the knife to cure the problem - something which would have ruled him out for up to six weeks.
But a second scan on the injury confirmed that surgery would not definitely heal the problem and Villas-Boas has therefore decided to put the player on a course of physiotherapy that will see him miss games against Maribor and Manchester City, but he could be available to face Arsenal in 10 days' time.
The Spurs boss said: "We could either give him surgery immediately, but there is no certainty it will cure the problem, or he could rest, have manual therapy, train in the swimming pool.
"That allows the player the possibility of return within 10-15 days, so we are taking that option at the moment, without having the surgery."
Whilst knowing he could have Dembele back for the Arsenal game is a boost, not having the player available for the team's next two games does disrupt Villas-Boas' plans.
Tom Huddlestone, fresh back in the team after a year-long ankle injury, has looked sluggish compared to Dembele, who offers drive and composure in the centre of the park.
Tottenham have won just one of the five games since the Belgian suffered his injury but Villas-Boas is confident he has the strength in depth to cope.
"We had good games without Mousa," the 35-year-old said.
"Against Chelsea we lost Gareth Bale and Mousa and we gave them a run for their money even though they were on an amazing run.
"We had extremely good games against Southampton and Norwich. Good players are missed but this squad is full of good players.
"I don't think it has affected the tempo and dynamic - it's more important to have players fully concentrated and motivated."
Villas-Boas is likely to play Huddlestone and Jake Livermore in midfield for Thursday's game against Maribor, providing the latter overcomes an ankle injury.
Another man who is likely to begin the game, which Spurs desperately need to win, is striker Emmanuel Adebayor.
Adebayor has not started a match for the club since he signed from Manchester City this summer, with Villas-Boas preferring to use Jermain Defoe as the team's target man.
Adebayor's lack of game time has led to suggestions the striker wants to leave the club, but Villas-Boas played down those claims.
"Certainly there is no interest in selling or loaning (Adebayor)," the Tottenham manager said.
"We brought him in this season, unfortunately for him it hasn't been working out in terms of injuries.
"We have full belief in Adebayor, he is one of the greatest strikers in the world. Sooner or later he is going to be back in the squad."
Villas-Boas made winning the Europa League one of his priorities when he joined Spurs this summer, but his team have registered three disappointing draws so far against Lazio, Panathinaikos and Maribor.
With an away game in Rome next up, Villas-Boas has no doubt about the importance of Thursday's clash against the Slovenian champions.
"Even though a defeat doesn't mathematically disqualify us, it is a game we have to win," he said.
"We are in this competition to win it."