Borussia Dortmund chief executive Hans-Joachim Watzke has promised supporters that the club will not lose any more of their star assets in the summer.
Striker Robert Lewandowski will join Bundesliga champions Bayern Munich on a free transfer at the end of the season, while the likes of Marco Reus and Ilkay Gundogan have been linked with moves away from Signal Iduna Park.
Manchester United are reportedly keen to take Reus to Old Trafford and have also been linked with a move for Gundogan, along with Real Madrid.
The midfielder's contract expires next year but he has been offered a new deal and Watzke has denied suggestions that Dortmund will look to cash in on the 23-year-old.
"We would like to prolong with Ilkay. He has an offer on the table," Watzke told Sport Bild. "The decision will certainly not wait until the summer.
"We absolutely do not see the need to sell players who have an existing contract."