Doubts over Pep Guardiola's long-term future at Bayern Munich have made the club "sharper" ahead of the defence of their Bundesliga crown, according to Matthias Sammer.
Guardiola has entered the final 12 months of his three-year-contract at Bayern, with ongoing discussions in the German media over the future of the Catalan coach.
Although the Bundesliga champions remain hopeful of convincing the former Barcelona coach to stay at the Allianz Arena, speculation over a potential exit grew stronger when Guardiola said late last week that he does not want to become a "burden" for the club.
Qatar-based network beINSports reports that Guardiola has agreed to coach Manchester City next season following the expiration of his Bayern contract.
The Catalan's future beyond next summer has been discussed prominently by the German media in recent days, and Borussia Dortmund CEO Hans-Joachim Watzke put forward former BVB coach Jurgen Klopp for the Bayern job.
Former Bayern captain Lothar Matthaus, meanwhile, believes Jose Mourinho is a much better coach than Guardiola -- a statement Guardiola responded to by claiming: "That's not my problem."
Bayern attacker Mario Gotze also allegedly criticised Guardiola in public, even though the 23-year-old later claimed he was misquoted and has since said he is "very happy" in Munich.
"Gotze became the first player to test how lame the possible "lame duck" really is," broadsheet Frankfurter Allgemeine Zeitung commented.
The uncertainty led to whistles from the crowd towards Guardiola prior to their Audi Cup clash against Real Madrid on Wednesday.
Following the 1-0 victory against the Spanish giants, the fans celebrated with the team, and, addressing his postgame news conference, the Catalan commented: "Today the people in Munich are satisfied but maybe this will change tomorrow."
In a postgame interview with ZDF slightly earlier, Bayern sporting executive Sammer said that Bayern might "sometimes argue, but really the others do the talking all the time... it's like that and it has always been like that."
Last weekend, Bayern lost the German Super Cup final against Wolfsburg on penalties, and Sammer said this defeat only heated up the discussion.
"It [the defeat] doesn't change the world, but in spite of that we have to radiate that Bayern can't be beaten," he said.
"Right now everyone believes he's entitled to an opinion, but I can tell you it's not bad for us, it sharpens our senses.
"The coach does a fantastic job, works well with the team, we want to stay together and that's the secret."
Veteran midfielder Xabi Alonso also offered his thoughts, telling Spanish paper AS: "At every big club there is criticism when you do not win. We have a great coaching team."
However, the former Real Madrid player did not go into details when asked whether Mourinho -- who he worked with at Bernabeu -- or Guardiola was the better coach.
"I'm proud of the coaches I have had, but I am not going to say if Mourinho is better than Guardiola," he added.