Many Greeks hold Germany responsible for the harsh austerity measures imposed since the onset of the economic crisis in 2010, while some Germans have expressed resentment over the Greek bailouts, causing tensions between the two nations.
Rehhagel – reportedly hand-picked by German Chancellor Angela Merkel, who believes his personality and popularity in Greece can help improve Germany's image – is part of a special team which arrived in Athens this week.
On Tuesday, he met Greek Tourism Minister Olga Kefalogianni, the ministry said in a statement.
The 74-year-old was also given an award for his contribution to Greek sports, state broadcaster NET reported.
"We [Germany and Greece] are connected by friendship and a common culture," he told journalists before attending a friendly football match.
"Whatever happens, Greeks will remain our friends. We have to help countries that are down on their luck," he added.
Rehhagel told German daily Bild earlier this month that he knew his name was "very positively portrayed in Greece."
"After all, we won the Euro 2004 and nobody thought it possible. So it is with pleasure that I will go to encourage my friends in Greece," he was quoted as saying.