Mats Hummels is refusing to talk about his relationship with former Borussia Dortmund manager Thomas Tuchel, as the pair could be reunited at Bayern Munich next season, according to ESPN.
Hummels worked under Tuchel at the Westfalenstadion during the 2015/16 campaign and it has been reported that the two didn't always see eye to eye.
Following the sacking of Carlo Ancelotti in Bavaria, and Jupp Heynckes returning to Bayern until the end of the season, Tuchel has been linked with the managerial role at the Allianz Arena.
However, Hummels doesn't want to be drawn in on speculation, saying: "I'll comment on Thomas Tuchel when things get that far."
The 28-year-old did speak about the TSG Hoffenheim manager Julian Nagelsmann, who has also been linked with the manager role at Bayern.
"He is only two years older than me - but it's not impossible," Hummels said about Nagelsmann, the 30-year-old boss being a managerial equivalent to a wonderkid.
"The trend is heading towards tactically astute trainers who like to play four or five different systems. Nevertheless, if you consider Jupp Heynckes, who only explicitly demands a single one, that can also work.
"There are several approaches. But I am definitely in favour of having a German-speaking coach of a German team."