Mertesacker is helping his international pal adapt to life in England by telling Podolski to get an Oyster card and use the Tube to get to know London.
The Arsenal centre-half, 27, said: "It'll be good for Lukas if he uses the London Underground. He will gain fantastic new experiences, both sporting and personal, by doing this. It really helped bring me on and I think it will do the same for him.
"I've been in London just under a year. I recently went to the Deutsches Haus, Germany's Olympics fan house, on the tube.
"My journey took 40 minutes and it's totally relaxed over here. Nobody recognised me and I arrived in good time. It is thrilling to sit by yourself in a tube train."