2014 World Cup winning centre-back is set to re-join Borussia Dortmund from Bundesliga rivals Bayern Munich.
The 30-year-old left Signal Iduna Park for Bavaria at the end of the 2015-16 season and has won the Bundesliga in each of his three seasons with the German giants.
During his first spell at Borussia Dortmund, Hummels won the Bundesliga in both 2011 and 2012, as well as the German Cup in 2012. The following year they finished runners-up to Bayern Munich in the Champions League final.
In a statement on the club’s official website, Bayern Munich confirmed that had reached an agreement with Borussia Dortmund over a transfer of the player, but the two clubs had agreed not to release the details.
Mats Hummels made just 20 Bundesliga starts this past season as 23-year-old Niklas Süle established himself in the Bayern Munich first team under head coach Niko Kovač, alongside Jérôme Boateng. Borussia Dortmund themselves have a lot of young centre-backs in their first team, so Hummels’ experience will be much welcomed.