BORUSSIA Dortmund's Australian goalkeeper Mitchell Langerak is relishing his first Champions League start against Marseille despite chipping two teeth in Naples a fortnight ago.

The 25-year-old came off the bench for his first Champions League appearance when Roman Weidenfeller was sent off just before halftime in the 2-1 defeat by Napoli.

Langerak immediately saved a free-kick, but was powerless to prevent Lorenzo Insigne smashing home a second-half free-kick for the winning goal, with painful consequences.

The Australian chipped two front teeth on the post as he dived to try to stop the shot.

"It hurt, but the defeat was worse," said Langerak, who joined Dortmund from A-League side Melbourne Victory in 2010.

"It wasn't an easy match to come on in; it didn't go as well as we wanted.

"It's never ideal to lose your first game, but we've got a chance to make things right."

With Weidenfeller suspended for the Marseille game, Langerak will be between the posts at Signal Iduna Park and coach Jurgen Klopp has belief in him.

"We are in the comfortable situation that when Roman Weidenfeller drops out, then there is no need for sleepless nights with Mitch around," said Klopp.

The statistics support Klopp's confidence. Langerak has won 12 of his 13 games in a Dortmund shirt, including coming off the bench to help Borussia beat Bayern Munich 5-2 in last year's German Cup final.

With veteran Mark Schwarzer having blocked his path to the Australian team, Langerak is set to make his Socceroo debut in October's friendlies against France in Paris and Canada in London.

"Mitchell Langerak deserves to play in at least one of those games - he's earned it," Australia's coach Holger Osieck has said.

At 33, Weidenfeller is showing no signs of giving second best and is pushing for a place in the German squad, but Klopp knows Langerak wants to be No.1.

"There is no question that an exceptional goalkeeper like Mitch wants to be first choice," said Klopp.