The Borussia Dortmund chief says Jurgen Klopp would have problems putting out a starting XI if every transfer rumour turned out to be true
The Germany international has 18 months left on his Signal Iduna Park contract and has been linked with a move to Manchester United and Arsenal in the past, although the player's father recently claimed Carlo Ancelotti's side are ready to make a move for his signature.
However, Watzke has urged fans not to believe the rumours, insisting the midfielder has made no suggestion he wants to leave.
"If we believe everything in the Spanish media about players supposedly leaving us. We would have to worry about getting a team together," he told Bild.
"We do not know from Ilkay or his father [who is also his agent] that he wants to leave."
Gundogan has endured a frustrating season, missing all but one Bundesliga game with a back injury picked up on international duty in August.