The Schwarzgelben chief hopes the Germany international will stay at Signal Iduna Park amid Manchester United links, but dismissed fears the team would fall to pieces without him
The Germany international has been linked with Manchester United, with the Premier League champions reportedly making a bid according to German media.
With interest in Gundogan swelling, Watzke expressed his desire to keep hold of the player but insisted that it would not spell disaster for Die Schwarzgelben if they sold him.
"Of course you're always trying to keep your top players, this is completely normal and we want to extend Ilkay's contract," he told Sky Sport News. "But you also have to see a sale as an opportunity.
"In 2011, we lost Nuri Sahin, who was the Bundesliga player of the year and we recovered.
"Ideally, we manage it so that only one top player goes again this year, namely Robert Lewandowski."
The Pole had signed a pre-contract agreement to join Bayern Munich at the end of the season on a free transfer, just a year after the Bavarians paid €37 million to lure Mario Gotze away from Signal Iduna Park.