Pulisic has missed the last two Dortmund contests — losses to Stuttgart and Tottenham Hotspur — with a muscle injury. Meanwhile Sokratis was forced off against Stuttgart while Burki went down against Spurs with a head injury.
The American teenager returned to training Wednesday providing some hope he could feature for Bosz's struggling side but the manager admitted Friday the attacker is among those who will face fitness tests before the Schalke showdown.
"We still have a practice today and we need to test if Sokratis, Roman Bürki and Christian Pulisic can play," Bosz told media.
The manager may be running out of time to right the ship, as elimination from the Champions League on Tuesday compounded a run that has seen Dortmund win just once since the end of September — a DFB Pokal victory over third-division side Magdeburg.
The slide has seen Dortmund go from first in the Bundesliga table, down to fifth while rivals Schalke have ascended to second, three points ahead of Bosz's men.
Bosz understands the criticism Dortmund have received and acknowledges they must beat rivals Schalke on Saturday to recover their shattered confidence.
"[The criticism] is understandable," Bosz said. "I try to ignore it. Only the derby is important.
"The mood in the team is good despite the difficult situation and there was small progress against Tottenham [in the 2-1 Champions League defeat].
"I speak with the players, we train, but you only get confidence when you win a game. We showed at the beginning of the season that we can play well. We need a victory."
However, given the club's struggles, Bosz also understands he may pay the price if there is no upturn in results soon.
"I am a football coach and know that anything can happen," he added.