The 27-year-old Spain international joined Chelsea from Liverpool for a British transfer record fee of 50 million pounds last January, but has endured a forgettable year at Stamford Bridge.
He has scored only five goals in 35 appearances, played poorly most of the time and has started only one of Chelsea's last seven matches in all competitions.
He was an unused substitute in Monday's 2-1 win over previously unbeaten Premier League leaders Manchester City and only came on for the last 13 minutes of Chelsea's Champions League win over Valencia on December 6.
As a result he has been widely linked with a move away from Stamford Bridge for a cut-price 20 million pounds fee in the January transfer window, but Villas-Boas told reporters at Chelsea's training ground south of London, he was not for sale.
"It is true: Fernando Torres is not for sale at any price, not now or in the summer," said Villas-Boas ahead of Saturday's Premier League clash with Wigan Athletic.
"We are pretty sure when Fernando is called up he will respond with the quality and talent he has. We have to make the best decisions for the team."
The Portuguese also gave unsettled England midfielder Frank Lampard, who like Torres has lost his place in the starting line-up, a boost.
The 33-year-old Lampard, who has been at Chelsea for 10 years and made more than 500 appearances for the club, came off the bench to score the winner from the penalty spot against City on Monday but has been recently sidelined while Villas-Boas has played Raul Meireles and 20-year-old Oriol Romeu in midfield.
"Frank Lampard is a player of massive magnitude to this club," Villas-Boas enthused. "There are plenty of players that push for the starting eleven and Frank is not the only one.
"I think 'Lamps' is one of the top five players most used. Every player wants to be involved in every game but sometimes it's just not possible.
"We've been having conversations with all the players, we treat them all equally. The club's direction and fortune is the most important thing.
"There is no hiding that 'Lamps' represents the best in the history of the club. These are players of massive magnitude and represent Chelsea's success but in our opinion every player must be treated equally. Sometimes we can't please everybody."
