Schalke's game against Hertha Berlin on Wednesday is set to go ahead despite a third coronavirus case in the squad.
Schalke is already relegated but its last three games of the season are against teams with much still to play for.
Schalke has condemned the fans who police said pelted players with eggs hours after the team was relegated from the Bundesliga.
James Rodriguez shone for Bayern Munich, scoring a goal and winning a penalty, as the German champions registered a 2-0 victory at Schalke to stay top on Saturday.
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.
Dortmund desperately need a win at home to second-placed Schalke to break their negative run and relieve the pressure on Bosz.
The German champion says Neuer was injured in training on Monday but the full extent of it won't be known until after medical scans.
German World Cup winning centre back Benedikt Hoewedes is all set to join Italian side Juventus n a hastily arranged transfer after being stripped of the captaincy at Schalke.
Robert Lewandowski took his season tally to 30 goals to inspire Bayern Munich's 3-0 win over ten-man Schalke.