World Cup winner Mario Goetze admits the metabolism disorder which sidelined him for five months is 'now part of his life', with the Germany star poised to resume playing on Saturday.

Borussia Dortmund host arch-rivals Bayern Munich for the German Super Cup -- the annual pre-season clash between the German Cup winners and Bundesliga champions respectively -- on Saturday.

It will be Goetze's first competitive match since withdrawing from all football in February, after featuring in Dortmund's pre-season friendlies.

"I feel good. I can take part in top level sport again, but I'm still in treatment through the medication that I have to keep taking," Goetze told German magazine Kicker.

"Everyone has their strength and weaknesses and the metabolic problem is a part of my life now.

"I am just happy to be back and able to do what I love."

After a lengthy spell on the sidelines, Goetze knows he needs time to rediscover his form.

"I am not going to come back and be 100 percent straight away after five months in rehab," he said.

"Of course, I will need the games and training sessions to refind my rhythm. That's obvious to me and, hopefully, to everyone else too."

It was Goetze's stunning chest and volley in extra-time at Rio de Janeiro's Maracana Stadium which won Germany the 2014 World Cup final against Argentina.

Three years later, Goetze, still only 25, is far from assured of a place in Germany's squad for next year's tournament in Russia.

A frustrating three-year stint at Bayern Munich, whose then-coach Pep Guardiola made it clear Goetze had no place in his first-choice line-up, ended in July 2016 when he returned to Dortmund.

It seemed the perfect place to rekindle his career after Goetze broke into the Germany squad on the back of helping Dortmund win the 2011 and 2012 Bundesliga titles under Jurgen Klopp.

- 'No Rio bonus' -

But Goetze struggled for any kind of form in his first season back, which was cut short in February when his disorder was unearthed and therapy began.

He says there were dark days in the first few weeks after the diagnosis.

"At first, it was hard for me to understand that I couldn't play even though I didn't have a structural injury, no damaged muscles or torn ligaments," said Goetze.

"It meant I had to have a time point to work towards - the start of the new season and be able to play again. That is what I have been looking to the most."

Bayern have won the title for each of the last five seasons, but US international Christian Puliisc sees this as Dortmund's 'big chance to win the Bundesliga'.

The Super Cup showdown will see Dortmund test themselves against Bayern under new head coach Peter Bosz, as striker Pierre-Emerick Aubameyang goes head-to-head with Bayern's Robert Lewandowski.

For Goetze, the Super Cup is also a chance to impress Germany head coach Joachim Loew before next month's World Cup qualifiers against the Czech Republic and Norway.

"Rio was an incredible event, but it doesn't carry a bonus anymore," admitted Goetze on his Russia 2018 hopes.

"Only the best will go to the World Cup, and Loew will decide."