For today's derby against Arsenal, his father Chris, who saw action in the Falklands with the RAF and was stationed in Germany, will be supporting his son, but he will waver when Spurs entertain Everton later this month, let alone if the German Under-21s meet England at the European Championship this summer in Israel.
"He's already told me that he will sit in the Everton end with his blue shirt with Holtby on his back," said Holtby Jnr to the Mail on Sunday.
"As for international football, well it could happen this summer. What makes it worse for him is that he brought me up English. I'd get bought English football shirts for Christmas. We'd support England together. In 2006 at the World Cup we were with 40,000 English fans in a public viewing area in Cologne watching England play Sweden.
"Ever since I chose to play for Germany he's been calling me 'Fritz'. I love the English black humour, of course. When we watched Germany beat England in the last World Cup, Dad was shouting about the Frank Lampard goal that wasn't given and I just sat there keeping quiet. Mum's the same. She supports Germany and backs me but she keeps quiet, too.
"I'm 100 per cent behind playing for Germany, though. They have really helped me develop and I'm proud to represent the country I have lived in all my life until now."