Manchester United and Chelsea have been put on red alert after Benfica revealed that Axel Witsel can go for the right price.
The Premier League duo have both been linked with moves for the 23-year-old, while Real Madrid are also rumoured to be interested.
According to Dutch newspaper De Telegraaf, Benfica have now slapped a £20m price tag on Witsel, who joined the Portuguese outfit for £6.3m from Standard Liege last summer.
Witsel, who plays in midfield, has won 28 caps for Belgium.