Soldado has repaid the Portuguese coach with four goals in his three games so far, but Villas-Boas said that the England international still has a part to play for Spurs this season.
"I think he will be here after the closure of the transfer window," the 35-year-old told reporters. "He has delivered the goals when we wanted. He has come on in the last two Premier League games and he has done extremely well for the team.
"He is a great professional with a great attitude and today he delivered a great performance.
"At the moment, we have played with one striker and Jermain and Soldado are competing for that spot with [Emmanuel Adebayor] out. There is competition and I think that is what is created in any big team."
Defoe weighed in with 15 goals in all competitions last season.