Borussia Dortmund expect striker Erling Braut Haaland to be sidelined with a leg injury until January, but defender Mats Hummels said his ankle issue is not as bad as first feared.

Haaland, 20, has claimed 17 goals in 13 games this season, including six in four Champions League games as the competition's joint top-scorer.

However, Dortmund coach Lucien Favre has confirmed the Norway striker "won't play again until January" with a torn leg muscle.

"That hurts us, but perhaps he has played a little too much recently," Favre added.

Haaland missed Wednesday's 1-1 draw at home to Lazio which put Dortmund through to the last 16 of the Champions League.

On Thursday, Haaland posted "great news! Spoke to my doctor and will be back soon" without giving details.

A win at Zenit St Petersburg on Tuesday will confirm Dortmund as Group F winners.

Hummels had to be helped off the pitch in clear distress after Lazio goal-scorer Ciro Immobile trod on his ankle late in Wednesday's game.

However Dortmund's centre-back said the problem is not serious as first feared.

"I'm just back from hospital. It looks like it's not so bad and could be good again in a few days," Hummels posted on Instagram.

Dortmund, who are fourth in the Bundesliga, currently have plenty of walking wounded as England midfielder Jude Bellingham, 17, limped off after the Lazio game.

Defender Thomas Meunier and midfielder Emre Can had already been ruled out with knocks.

"A few players are on their last legs," admitted sports director Michael Zorc with one eye on Saturday's league match at Eintracht Frankfurt.