RB Leipzig is controlled by the Austrian energy drink company and has been a big spender for several seasons as they climbed up the divisions with the Bundesliga now firmly in their sights.
They have moved up from the fifth tier in 2009 to the second tier last year, winning promotion three times in five seasons.
They also made more headlines this season after signing huge German talent and youth international, 20-year-old Davie Selke from Werder Bremen, luring him to the second division with a multi-million contract.
Under German football rules they cannot be called Red Bull Leipzig and are officially known as RasenBallsport Leipzig (grassball sport Leipzig) or RB Leipzig.
“Leipzig has again spent vast amounts of money on new players, almost all of whom had offers from the top division,” Union fan group ‘Scene Koepenick’ said in an open letter to Union fans. “The financial possibilities seem endless.”
“But we will fight for the preservation of football culture for as long as possible. Pure marketing instruments like RasenBallsport will never be part of that culture and that is why we call on a 15-minute silence.”
Union Berlin, located in the eastern part of the capital could not be more different to Leipzig, having a long reputation of an anti-establishment club going all the way back to the days of East Germany and fierce fan loyalty.
A club official told Reuters Union was fully behind the fan initiative.
“I can only use the words of our president Dirk Zingler who fully backs this initiative by 100 percent,” club spokesman Christian Arbeit said. “RB Leizpig can expect more protests.”
Union Berlin has close ties to its fans with hundreds of them helping rebuild their stadium a few years ago and organise blood donations to save the club. It also gave fans in 2011 the chance to own part of the stadium, by issuing 10,000 shares at 500 euros.
In February they extended the contract of veteran Benjamin Koehler by a year after he was diagnosed with cancer.
RB Leipzig are one of four clubs worldwide controlled by the drinks maker. The others are in Salzburg, New York and in Brazil.
(Editing by Amlan Chakraborty)