Manuel Neuer has named Borussia Dortmund, Schalke, Hoffenheim, Bayer Leverkusen and RB Leipzig as the likely challengers to Bayern Munich's Bundesliga title.

Niko Kovac's side begin the defence of their crown on Friday, when Julian Nagelsmann's Hoffenheim visit the Allianz Arena.

Bayern are going in search of a seventh league title in a row, having finished 21 points clear of second-place Schalke last season despite a troubled start that saw Carlo Ancelotti sacked as head coach.

Neuer thinks Schalke and Dortmund will again be close challengers, while he is wary of the threat posed by three other teams who qualified for Europe last term. 

"In particular, the clubs from the west: Dortmund, Schalke," he told Bild when asked who their closest rivals will be. "Hoffenheim will also have a role to play. We'll see what's what with Leverkusen and Leipzig."

Bayern will again be chasing a treble of Bundesliga, DFB-Pokal and Champions League this season, although Neuer believes it is dangerous to discuss their hopes of a clean sweep too early.

The Germany goalkeeper pointed to Dortmund's 2-1 DFB-Pokal victory at Greuther Furth on Monday, in which they required a 95th-minute equaliser from Axel Witsel and a strike from Marco Reus in the last minute of extra time to go through.

"It makes little sense talking about the treble before the season," he said. "You just have to look at Dortmund in the cup game at Furth: it can hit anyone. Dortmund only scored in the 120th minute to make it 2-1.

"In the cup games especially, a lot depends on the performance that day. A lot can happen.

"We have a strong team; we're well prepared for all competitions. We have a good back-up in every position and it will be difficult for the coach to choose the first team. Sometimes, there will be some surprises."