Borussia Dortmund are desperate for Chelsea to beat off rivals Bayern Munich and buy their star striker Robert Lewandowski.
The German side have let Chelsea know they will accept attacking midfielder Kevin De Bruyne as part of the transfer package.
The 21 year old Belgium international has yet to make an appearance for Chelsea since arriving from Genk in January 2012 for £7m. The youngster was loaned to Werder Bremen six months later, where he made 31 league appearances and scored 7 goals.
Dortmund- who face Bayern in the Champions League Final at Wembley on May 25- know that letting Lewandowski leave, will lower their chances of beating Bayern in the Bundesliga.
Bayern Munich have already started their raid on a young Dortmund side after signing the most expensive German player Mario Gotze in a £30m move.
Lewandowski, 24, who is rated at £25m by Dortmund, has already attracted Premier League sides Chelsea and Manchester United.
Real Madrid manager Jose Mourinho who has been linked to the Chelsea job, is understood to be a big fan of Lewandowski, who became the first player to score four goals in a Champions League semi-final as Dortmund beat Spanish champions Real Madrid 4-1 in their first leg.
Dortmund hope the De Bruyne idea could persuade the Blues to outmaneuver Munich and sway Lewandowski with a better contract offer.