A full-strength side offered little resistance at Borussia Park on Wednesday as Bayern suffered a club-record defeat in the German Cup.
Salihamidzic described Bayern’s performance as a ‘collective black out’ and demanded an improvement in east Berlin, where Union are unbeaten in their last 21 home league games.
“We want to give each other a short shake and step on the gas Saturday,” fumed the Bayern sports director.
Union are the only Bundesliga team who did not lose to Bayern last season when both home and away league games ended in 1-1 draws.
Bayern can expect a tough time at Union’s Alten Foersterei stadium, where they will need to tighten their defence after Dayot Upamecano and Lucas Hernandez looked vulnerable on Wednesday.
Urs Fischer’s Union have conceded just two goals in six home games this season.
Aside from Wednesday’s heavy defeat, it has been a week to forget for Bayern.
Hernandez discovered Wednesday morning that he will avoid being jailed in Spain despite violating a restraining order in 2017.
Joshua Kimmich sparked fierce debate in Germany last weekend after admitting he opted not to be vaccinated against Covid-19.
All the while, Bayern coach Julian Nagelsmann has been isolating at home after testing positive for Covid-19.