Jan Vertonghen, Michael Dawson, Steven Caulker and William Gallas have been competing for first-team action this season, while Younes Kaboul has been sidelined since August with a knee injury.
"It's a difficult one.” Villas-Boas told reporters. "We won't start another season with five centre-backs.
“We have five top central defenders at the moment - a mixture of young players coming through with lots of experience, and then you have such tremendous central defenders as William, Dawson and Younes Kaboul.”
Tottenham accepted a £9 million bid for Dawson from QPR during the summer only for the player to reject the move and subsequently find opportunities at White Hart Lane limited.
But, after Dawson forced his way back into Villas-Boas’ plans, the Spurs boss is delighted to have retained the four-time England international.
"I think we appreciate the fact we were able to hang on to [Dawson],” he continued.
"We ended up being on the better side by the fact he agreed to stay with us. We were lucky in that sense."
When asked whether 35-year-old vice-captain Gallas would be in line for an exit, Villas-Boas was keen to highlight the importance of the Frenchman but did not rule out a summer move.
"William has been a massive player for us this season.” Villas-Boas stated. “He's a player we trust a lot.
“Whatever we decide regarding his future, we'll have to wait and see, but we are aware of what a presence he's been for us this season."