Bastian Schweinsteiger wrote to a former Bundesliga referee who attempted to take his own life in 2011 to express his concern and support, Swiss newspaper Blick has reported.
Schweinsteiger contacted Babak Rafati, 46, who made an attempt on his own life while still working as a referee in November 2011.
Rafati told Blick the midfielder, who was then 27 and playing for Bayern Munich, had written: "Mr Rafati, there's often setbacks in life. But you have to bounce back each time. I wish you all the best."
He said he had appreciated Schweinsteiger's concern for his situation, saying: "I was very deeply moved.
"He didn't have to do that. He knew I would never referee again after this incident. It was an incredibly humane gesture."
Rafati said "depression is still a massive taboo subject in football" and alleged that the German FA (DFB) had put him under pressure at the time of the attempt "after I had revealed certain unpleasant truths."
He added: "Then I started to make mistakes, I found myself alienated and wasn't allowed to officiate in the Bundesliga for weeks."
Rafati, who has written a book about struggling with depression during his refereeing career, said he was working with three Bundesliga players as a mental trainer.