The father of Stuttgart captain Christian Gentner died in the stadium immediately after the Bundesliga side's 2-1 win over Hertha Berlin on Saturday.
Stuttgart said the club are "mourning the loss of Herbert Gentner" and that their thoughts are "entirely with the Gentner family at this difficult time".
The BBC reports that it is not clear as to what caused the death of the senior Gentler as autopsy reports are yet to be filed.
Christian Gentner is a 33-year-old veteran of the game who has played five times for the German national team.
Gentner had provided an assist for fellow veteran Mario Gomez to score the winner for Stuttgart.
But the losing side, Hertha Berlin, were one of the first football clubs to sympathise with Gentner and Stuttgart.
The capital club wrote on social media: "Everyone from Hertha would like to send their thoughts and condolences to Christian Gentner and his family after today's sad news."
Other German clubs sympathised with the bereaved and the club.
With two matches to the end of the first round of Bundesliga 2018/2019, Stuttgart are 15th with 14 points.
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