Mats Hummels must endure the anger of Borussia Dortmund fans to be a success at Bayern Munich, Christoph Metzelder has warned.
Bayern announced on Tuesday Hummels has agreed a five-year contract and will move to Allianz Arena on July 1, subject to passing a medical.
Dortmund publicly confirmed last month the centre-back had informed them of his desire to move back to his former club, prompting an angry response from some BVB supporters in the 5-1 Bundesliga win over Wolfsburg.
And former Dortmund defender Metzelder, who incurred the wrath of Signal Iduna Park when he joined arch-rivals Schalke from Real Madrid in 2010, says Hummels must be ready to cope with similar treatment.
"He has family roots in Munich. He has the chance to win a lot of titles at Bayern, including the Champions League. I can understand that," he told Sport Bild.
"As a player you always feel unfairly treated because it is believed that there are rational and understandable explanations.
"But the fans' point of view is just a sum total of emotions. So you can understand why the fans are upset when the captain goes back to a big rival.
"I've experienced it myself after my move to Schalke. Mats can and must endure it."
Metzelder believes the signing is a direct response to Bayern's defensive worries during Jerome Boateng's injury-enforced absence this season, and thinks Hummels' arrival could give the Bundesliga champions the best backline on the continent.
"It's an effect of facing Atletico Madrid this season, although even against Juventus they had too great a loss of quality in the defence due to injury," the 35-year-old said.
"Boateng and Hummels in one side - that would be impressive, the best defence in Europe.
"Jerome has evolved under Pep Guardiola. He is perhaps the more complete of the two, because he's better in the defensive battles and has the speed.
"Mats, by contrast, is an incredible strategist who has huge self-confidence, and is perhaps the best at playmaking."
