Borussia Dortmund have not yet reached an agreement with either Bayern Munich and Mario Gotze over the Germany international's return, CEO Hans-Joachim Watzke has said.
Gotze, 24, is expected to return to Dortmund three years after his controversial €37 million switch to the Allianz Arena, with Bayern CEO Karl-Heinz Rummenigge saying at the weekend: "He's been here for three years and it's not worked out.
"I wouldn't say a deal has been struck, but I can confirm that there have been talks with Borussia Dortmund as well as with his agent."
Speaking to Munich-based paper TZ, Watzke confirmed: "We have not reached an agreement with anyone, including the player. It has to be financially feasible for us."
According to a report in kicker on Monday, Dortmund are prepared to pay around €25m for Gotze, who scored 35 goals in 109 competitive appearances for Bayern, but the German champions are holding out for more.
On Thursday, Dortmund depart on a nine-day tour of China, and Watzke said that "thanks to modern communication" talks could go on during the trip to Shanghai and Shenzhen.
Meanwhile, Bayer Leverkusen have said defender Omer Toprak, 26, will not join Dortmund this season, with kicker claiming that the centre-back will make the switch to the Westfalenstadion next summer instead.
The Turkey international can activate a €12m release clause in his contract next summer but Leverkusen sporting director Rudi Voller told Bild there will be no deal this summer.
"It's top news that Omer stays," Voller said. "It's the best solution for us. We are very happy about it."
Bild reported that Dortmund had offered €22m this summer but Leverkusen were holding out for €25m.
"We were willing to talk," Voller said. "No agreement was reached. It wasn't our fault."