Defoe appears to be behind summer signing Roberto Soldado in the Spurs striking order and the 31-year-old has started just once in the Premier League this season.
However, Defoe has featured regularly in the cup competitions, finding the net nine times in seven outings in the League Cup and the Europa League.
When asked if Defoe could leave Tottenham in the winter transfer window in a bid to enhance his chances of being selected in England's World Cup squad this summer, Villas-Boas replied: "No, I don't think so."
The Portuguese boss further told reporters: "We are pretty happy with the goals he is producing. He is on nine goals already so it is a great start for him and it doesn't change our perspective regarding his position in the team.
"I'm not sure about the selection process for [England manager] Roy Hodgson, but from what I have seen he has been counting on Jermain in the same way and he has been included in all call-ups since we started playing this season."
Defoe became Tottenham's all-time leading goalscorer in European competitions by netting a second-half penalty in Thursday's 2-1 win over Sheriff Tiraspol.