Nadiem Amiri has accepted an apology from a Union Berlin player who verbally abused him when the Bundesliga teams played Friday.
Chelsea have already acquired another Bundesliga star, Leipzig striker Timo Werner, for an estimated 53 million euros.
In the Europa League quarter-final match, Inter Milan registered a 2-1 win over Bayer Leverkusen here on Tuesday.
The team showed its domestic dominance by beating Bayer Leverkusen 4-2 in the country’s first cup final held without supporters present, due to the coronavirus pandemic.
Kai Havertz scored the sole goal of the match and hobbled off just past the hour with an apparent injury.
Holders Bayern Munich will host Eintracht Frankfurt while Bayer Leverkusen face fourth-tier side Saarbruecken.
RB Leipzig said that their security staff had been instructed to intensify checks of certain groups due to potential risk.
A first-half goal from Guido Burgstaller fired Schalke to a 1-0 victory over Wolfsburg and a place in the semi-finals of the German Cup.
Champions Bayern Munich opened the 2017/18 Bundesliga season with a 3-1 win over Bayer Leverkusen on Friday.
Should Dortmund reach the last four, it will set up a repeat of last year's final, which Bayern won on penalties.