Bayern Munich midfielder Leon Goretzka may require surgery to rectify the troublesome knee injury that has kept him out of action for over a month, according to Die Roten coach Julian Nagelsmann.

The Germany international, who has two goals and two assists in 12 Bundesliga appearances this term, has not taken to the pitch since Bayern’s 3-2 win over rivals Borussia Dortmund on 4th December, in which he managed just over an hour after struggling with a previous knock. 

Speaking ahead of the champions' home match against Borussia Monchengladbach, revealed that a decision on whether he requires surgery is due in the next couple of days.

"It's complicated." Nagelsmann said of the situation. "He [Goretzka] had two good days of training, then we had to decrease the strain [on him]. His physical condition was a lot worse.

"We examined him again and we did an MRI scan, but we couldn't detect anything.

"So, we sent him to another specialist, who will examine him again and decide what we're going to do; whether we can keep treating it conservatively, or if we have to open it up and have a look.

"In the next two days we'll decide what we need to do."

Any long-term absence for the former Schalke midfielder, who has won three Bundesliga titles and one Champions League since arriving at the Allianz Arena in 2018, would be a severe blow to the hopes of Nagelsmann's side, whose preparations for their return to Bundesliga action have been hampered by a number of players contracting COVID-19. 

The former Hoffenheim coach did not hide his frustration at Goretzka's situation.

"What is clear is that we can't keep going this way. The situation is bad for him, and bad for the club.

"Of course, we all want him to play, and he wants to play, but that's not possible. We have to think about a couple of new paths that we could go down."

Bayern have won their past five Bundesliga matches to open up a nine-point lead at the summit, but will still be keen for the return of their midfield mainstay, who was named in the Bundesliga team of the season last campaign.