Bale was again missing with a buttock injury as Spurs completed their Asia Trophy campaign with a 6-0 victory over South China to secure third place.
His absence did not spare Villas-Boas the usual round of questions about his star player's future in the wake of a report in Spain which claimed Bale has told Tottenham he wants to join Real Madrid.
The manager adopted his now-familiar poker face as he said: "I won't comment on anything. I am so sorry. I can't speak about speculation."
But he was more forthcoming on Bale's fitness, saying: "He is going to be fit to join the team for training on Wednesday. There is a big possibility he could be fit for Monaco.
"He hasn't done any training with the team yet but in all of the pre-season friendlies we had before he was involved. We are confident he will be able to join us."
Tottenham continue to insist Bale is not for sale, while the player has given no public indication this summer that he is seeking a move elsewhere.
Villas-Boas said on Friday that talks between Bale's representatives and Spurs officials over an improved contract were "ongoing".