Lucas Hernandez sustained an adductor problem during Bayern Munich's demolition of Fortuna Dusseldorf, Hansi Flick has confirmed.
In the only change from the Bayern side that beat title rivals Borussia Dortmund 1-0 on Tuesday, Hernandez replaced Jerome Boateng in the centre of defence.
It was the France international's second start in all competitions this year, having spent three months out with an ankle ligament injury he suffered in October.
Hernandez - an €80million signing from Atletico Madrid ahead of the 2019-20 season - was replaced by Michael Cuisance at half-time on Saturday as Bayern held a 3-0 lead, with Joshua Kimmich moving to centre-back.
Flick revealed the decision was a precautionary measure.
"He had an adductor problem. Considering the score, the risk was too high, we didn't want to take it," said Flick.
An eighth straight Bundesliga title now looks a certainty, while they are in the DFB-Pokal semi-finals and have a 3-0 lead in their Champions League last-16 tie with Chelsea, and Flick praised the mentality of his players.
They took the lead via an own goal from Mathias Jorgensen and extended their advantage through Benjamin Pavard and Robert Lewandowski.
Lewandowski scored his second four minutes into the second half and Alphonso Davies rounded off the scoring in a comprehensive triumph soon after.
"We want to have a successful season but there is still a lot left to play," Flick told Sky.
"It was important to me that we didn't let up after the Dortmund game. I am very, very satisfied, we were very aggressive.
"We push each other in the team because the emotions don't come from the stands, you hear that a little more on the pitch."