Chelsea and Manchester City are on the alert after debt-riddled Valencia agreed to sell striker David Villa.
Villa's teammate Silva is also available and Manchester United is sure to fancy the attacking midfielder, who may fetch up to £20 million.
The Spanish team wants to raise £50 million by selling both players, but Villa could cost £40 million alone if a bidding war erupts between the Premier League's richest clubs.
Insiders say Villa, who has scored 121 goals in 223 outings for Valencia and 37 in 55 internationals, will also be wanted by Barcelona and Real Madrid, The Sun reports.
But he is likely to prefer a move to the Premier League, with Chelsea being his first choice.
Nicolas Anelka is stalling over an extended one-year deal at Chelsea and Blues fans would view Villa, 28, as a good replacement.
Villa said: "For now my head is in Valencia and the World Cup. After South Africa I will decide what's best. My final decision won't be based solely on money."
