Former England head coach Steve McClaren was unveiled as the new Nottingham Forest manager at a press conference at the City Ground this morning.
The 50-year-old, who as assistant to Jim Smith helped lead East Midlands rivals Derby to promotion to the Premier League in 1996, returns to English club management after a five-year absence.
McClaren agreed a three-year contract on Monday to succeed Billy Davies who was sacked the previous day.
Low added on www.dfb.de: "For a decade, Michael Ballack has been a leading player in the national team and had an enormous stake in the success of the team since the 2002 World Cup.
"His ability and class speak volumes, as do his eye for goal and his nerves of steel, especially in big games.
"We (the DFB) would like to say a sincere thank you for his great contribution to German football."
DFB general secretary Wolfgang Niersbach added Ballack would be invited to make a 99th and final appearance in a friendly against Brazil in August.
"He has known about this fixture for a long time, we hope he accepts the offer," said Niersbach.
Ballack made his name at Kaiserslautern before joining Leverkusen in 1999.
Four-year spells at Bayern Munich and Chelsea followed before he returned to Leverkusen at the start of last season.