Borussia Dortmund say Mats Hummels is set to leave this summer.

Dortmund have confirmed Hummels has asked to leave the club and re-join Bundesliga rivals Bayern Munich this summer.

The defender has been linked with Liverpool, Manchester United and Manchester City.

In a statement announcing the news, Dortmund said: "Defender Mats Hummels has communicated his desire to leave the club in the summer and join league rivals Bayern Munich next season.

"Borussia Dortmund's board has decided to make such a change depending on whether Bayern Munich produce an offer of the right value. So far, Bayern Munich have not made an offer.

"It is pointed out that no exit clause has been agreed and the player is tied to Borussia Dortmund until June 30, 2017."