Thiago suffered an ankle injury in the DFB Pokal on Tuesday.
Bayern Munich's Thiago Alcantara is "in a lot of pain" and will need to undergo a medical examination after sustaining an ankle injury during the Bavarian's DFB-Pokal victory on Tuesday, according to manager Niko Kovac.
Thiago, 27, limped off the field of play with 15 minutes left on the clock after receiving treatment on the sidelines against Rodinghausen, leaving Kovac to sweat over the fitness of one of his key midfielders.
The nature of the victory was unconvincing but Bayern's win ensured they progressed into the third round of the competition, alleviating a bit of pressure off Kovac after a slow start to the season.
However, the win came at the cost of Thiago who has become an integral member of Bayern's midfield in the absence of Corentin Tolisso - who sustained an anterior cruciate knee ligament injury in September.
Kovac confirmed after the match that the club will know more on Thiago's injury prognosis on Wednesday as he said, via the club's Twitter: "He's in a lot of pain at the moment, but we will wait and see what the examination reveals [on Wednesday]."
The German outfit now face a nervous wait for the 27-year-old's results as a report from FourFourTwo claims he was seen leaving the stadium on crutches, ensuring Kovac was left to fear the worst.
"We don't know what it is yet, but it doesn't look good," he said.
Thiago has missed just one game for Bayern this season and his injury comes as a major source of frustration for the club after seeing the likes of Leon Goretzka, Arjen Robben, Mats Hummels and Rafinha all succumb to injury issues in the early stages of the season.
The Bundesliga giants will host rivals Freiburg on Saturday in the first of their three games in seven days, before turning their attentions back to the Champions League ahead of their trip to face league leaders Borussia Dortmund.