Borussia Dortmund are in closing on a shock return to the Westfalenstadion for Bayern Munich defender Mats Hummels.
The 30-year-old looks set to return to his former club in a £27million deal, having won three straight league titles with Die Roten.
Talks between the two clubs are at an 'advanced' stage after initial contact was made this week.
Hummels came through the ranks at Bayern, where his father was a youth coach, before joining Dortmund on loan in 2008 under Jurgen Klopp.
He completed a permanent move for just £4million the following year, going on to win two Bundesliga crowns at the Signal Iduna Park, as well as reaching the 2013 Champions League Final.
The World Cup winner returned to Bayern in a £30million transfer in 2016, but his place is far from secure under Niko Kovac.
Hummels started just 20 league games last term and his place is set to be taken in the starting XI by French defender Lucas Hernandez - signing from Atletico Madrid for £72million.
Hernandez, although first choice left-back for his country, is set to be used at the heart of defence in Bavaria, with David Alaba remaining the No.1 choice at left-back.
As such, Bayern are ready to cash in on Hummels, who was unceremoniously dumped from the Germany squad by Jogi Loew earlier this year too, and Kovac is happy to cash in on a player who turns 31 in December.
A return for Hummels was mooted to CEO Hans-Joachim Watzke back in April, when he appeared on Sky TV in Germany.
At the time, Watzke appeared to dismiss a potential return, stating: "I believe that Mats will remain at Bayern Munich. I’m sure, I’m convinced of that.
“We have four centre-backs for the new season, plus we've still got (Leonardo) Balerdi.
“[But] You should never rule out anything fundamentally in football, I've learned that over the years, but you can forget about the topic.”
Dortmund took the title race to the final day in 2018-19, but Lucien Favre is keen to add more experience to a young and somewhat fragile defence.
Hummels is unlikely to be the only experienced man to leave Bayern, with Jerome Boateng by president Uli Hoeness.
