The north Londoners come to Slovenia third in Group J following draws in their opening matches at home to Lazio and away to Panathinaikos.
Now comes a double-header with Maribor, starting with Thursday's clash at the Stadion Ljudski vrt before the return fixture at White Hart Lane two weeks from now.
"I think these two games with Maribor is going to be the decisive point of the group phase," Tottenham boss Villas-Boas said.
"A point will not be a bad result as it will keep us tight with Maribor. Lazio can escape if they beat Panathinaikos tomorrow.
"But our two games with Maribor will be decisive. After those we will see where we stand, before we have a home game with Panathinaikos and a difficult trip to Lazio.
"I think these two games could prove decisive. You will get a clearer picture after these two games to see more or less what can we do."
Maribor were defeated in the group stage by second-tier Birmingham in last season's competition and asked whether they were a side Tottenham should be beating, Villas-Boas said: "Yes, for the players we have and the team that we have this is clear.
"But it doesn't always go like that and that is the reality of the game. You saw only yesterday Manchester United struggling against Braga - two teams of completely opposite dimensions.
"By the nature of the game, we will not expect an easy game. It is a passionate environment, a very, very good club that are run tremendously and have done very well in the last 10 years, winning most of the Slovenian titles."
Villas-Boas has brought a strong-looking 19-man squad with him to Slovenia, although he will have to do without several key names.
Mousa Dembele remains sidelined with a hip complaint and goalkeeper Brad Friedel has stayed at home, meaning Hugo Lloris will start the game.
Bale also stayed in the UK after his girlfriend gave birth to their first child at the weekend, which saw him miss the 4-2 home defeat to Chelsea.
"We've been discussing it since he left us for the game against Chelsea, so he is allowed to stay with his family until tomorrow," Villas-Boas said. "It's a conversation I had with him.
"I think on such an important date, it's important to give the player the choice of return, so he returns mentally strong and ready to focus on the game.
"It depends case to case. It's all very emotional for him at the moment, like it has been for a couple of us here, so I think it is the right time for him to be off so that we have no doubts about his mental state when he returns for Southampton.
"In these occasions, it's important to have the input from the player. We left it up to him to decide on the Chelsea game.
"Obviously it was an important date for him and we allowed him to go back to his family. It's the normal amount of time."
Adebayor is the other big name not to have travelled with Tottenham, which Villas-Boas says is due to back pain.
However, there were reports the Togo striker could ask to miss the trip to Slovenia as he was unhappy about his chances of winning a starting berth.
"He's pretty happy," Villas-Boas said of Adebayor. "I think we have got some excellent results that came to an end at the weekend against Chelsea, but the group has been extremely happy.
"Obviously each individual has their own position. There are people playing, people that are injured and those threatening to come in.
"Certainly Ade is a player who wants to come into the team, but Jermain Defoe's form and the structure that we are using now, plus the injury setback he suffered after the Reading game, hasn't allowed him the playing time that he deserved."
Tottenham (from): Lloris, Cudicini, Naughton, Walker, Caulker, Gallas, Dawson, Vertonghen, Smith, Livermore, Parrett, Huddlestone, Sandro, Sigurdsson, Lennon, Townsend, Falque, Dempsey, Defoe.