Holtby only moved to White Hart Lane from Schalke in January last year, but has failed to make the expected impact at the club.
Holtby has recently been linked with a return to the Bundesliga and Borussia Dortmund are reportedly interested in signing the defender.
“My feeling is he will leave but it’s not in our hands at the moment,” agent Marcus Noack explained.
“Tottenham have to agree to let him go first. We hope to find a solution in the next couple of days.”
“I think it will be a loan because it is difficult for anyone to buy Lewis,” he added.