Borussia Dortmund full-back Marcel Schmelzer is set to miss six weeks after sustaining an ankle injury in Saturday's goalless draw against Freiburg.
The club confirmed on Twitter that the Germany international will be absent for over a month following the ankle ligament damage.
The 29-year-old, who was making his first appearance since his recovery from a similar injury in pre-season was withdrawn in the first half at Schwarzwald-Stadion.
An MRI scan has since revealed that Schmelzer ruptured ankle ligaments in his right foot having been tackled by Freiburg's Yoric Ravet, who was sent off for the challenge.
"It looks like it could be a recurrence of the same ankle injury, judging by how it feels," said Dortmund press officer Sascha Fligge immediately after the game.
BVB boss Peter Bosz could be left with even more concern over his defensive options after Marc Bartra was withdrawn after just 18 minutes with a groin problem.
The two defenders join Marco Reus, Raphael Guerreiro, Andre Schurrle, Erik Durm and Sebastian Rode on a growing injury list at the Bundesliga club.
Dortmund's midweek trip to Tottenham in the Champions League is the first of a busy schedule that includes six games over just 17 days.
"We're disappointed,” coach Bosz said after the draw at Freiburg. “Dortmund should win in Freiburg.
“If you're playing with an extra man for an hour, you have enough time to score a goal. We didn't do enough today. We see the result as two points dropped."