The Germans suffered a 73-47 defeat at Ukraine on Wednesday night in the EuroBasket Women Additional Qualifying Round, three days after the Ukrainians had come from behind to win at Bulgaria.
Only the side that tops Group A will advance to the Final Round in Latvia this summer.
"The team that loses on Saturday is out and won't have any chance to come in first in the group," Szittya said. "We knew from the beginning that we would have to win our home games. That's what we have to do in Hagen against Bulgaria."
On the playing personnel front, Germany will be boosted by the return of guard Sarah Austmann, a member of their squad that played at the EuroBasket Women in Italy two years ago.
A virus knocked her out of the Ukraine game.
"We will adjust her time on the court to her current strength," Szittya said.
Bulgaria will like their chances of getting a win in Germany, particularly with the exciting TEO Vilnius star Noel Monik Kuin now in the squad.
The naturalized player from the United States had 19 points while another big part of the offense that will cause trouble for Germany should be Gergana Branzova-Erdenay, who had 18 points against the Ukrainians.
"Kuin is a top player performing for Vilnius in the EuroLeague," Szittya said. "She excels offensively and puts a very high intensity on the court - just like the whole Bulgarian team."
The Germans' struggles in the scoring department could continue with the absences of Linda Fröhlich and Anne Breitreiner. The latter has an Achilles tendon injury while Fröhlich isn't able to play because of contractual issues with her club side.
Ukraine In Driver's Seat
|Olexandra Gorbunova in action for Ukraine|
Olexandra Gorbunova underlined her status as one of the top players in European basketball last summer by leading the EuroBasket Women Division A in scoring.
In the Additional Qualifying Round, she has been sensational in Ukraine's two victories, including Wednesday's triumph over Germany when she scored 20 points and grabbed nine rebounds.
"The result was badly needed," she said. "We gained the win and that is the only thing that counts. The win should give us enough confidence before the next game against Bulgaria.
"We have only one week left to prepare well for the game.
"Germany played without some of their key players today and we do not know yet if they are going to play in the second game.
"We made the first two steps towards qualification but we have two more still to take. We will try to stay focused and hopefully we will prepare well for the road game in Germany."
Dijon-Gérardin Requires Finger Op
France international center Sandra Dijon-Gérardin suffered a finger injury while playing in the national team camp during the winter break in Monaco which requires an operation.
Dijon, who played for Latvian outfit Cesis in the EuroCup Women, will be sidelined for four weeks.
Ekaterinburg center Sandrine Gruda missed Les Bleues' successful EuroBasket Women 2009 qualifying campaign but is with the national side in Monaco.