Group leaders Germany depleted by injuries
Germany have a maximum 15 points from five qualifiers and another two victories against Austria and Azerbaijan on June 7 could see them all but through to next year's finals in Poland and Ukraine.
Coach Joachim Low, however, has fitness doubts over Sami Khedira while fellow midfielders Bastian Schweinsteiger, Christian Trasch and Sven Bender are definitely ruled out by injury.
If Khedira makes it back for the game in Austria after a thigh problem, Low may opt for Toni Kroos as his midfield partner.
Germany also have only one out-and-out forward in Mario Gomez after Marco Reus and Miroslav Klose were sidelined.
Gomez finished as the Bundesliga's top scorer this season and also netted in Sunday's 2-1 friendly win over Uruguay.
Whether or not he can sustain that level of form for their qualifiers against Austria and Azerbaijan will be the litmus test for the 25-year-old as he tries to wrest the permanent starting spot from Klose.
"We have decided not to bring other players in because we trust the current squad," Loew said on Wednesday.
Austria have seven points from five games and coach Didi Constantini is playing one of his last cards as he bids to keep alive the fourth-placed team's slim hopes of reaching the finals.
Constantini has dropped forward Marko Arnautovic who has scored three goals in the qualifying campaign but performed poorly in successive defeats by Belgium and Turkey in March.
The weight of goal-scoring expectations will now fall on captain Marc Janko as Austria search for a first competitive win over their neighbours since the 1978 World Cup.
"We are the clear outsiders but that also means we have nothing to lose," said Janko. "We want to anger our big brother and maybe it will be enough for a draw or even a sensation.
"We are in a position where only victories will do for us right now."