Benfica president Luís Filipe Vieira admits they must sell again in January to balance the books.

Vieira says he won't risk the club's future by continuing to pay big wages to his current squad.

"Those who think we can continue to live like a few years ago are sadly mistaken, whoever persists in this error will end badly. Sell, buy less and train more. Sell and lower wages, even if it means sacrificing our competitiveness," said Vieira.

The prime name to be cashed in for January is winger Nicolas Gaitan, who is a top target for Manchester United, Manchester City and Liverpool.