Leipzig's Nkunku in doubt for Man City clash with muscle tear
RB Leipzig announced Nkunku had "suffered a thigh strain" in his side's 2-1 loss at Borussia Dortmund on Friday and "is set for a spell on the sidelines."
Leipzig play on March 11 at home to Borussia Moenchengladbach before travelling to Manchester City for the second leg of their Champions League last 16 tie.
Leipzig drew 1-1 with the English champions in Germany.
Leipzig also announced that midfielder Xaver Schlager "will be out for a long time" and will go under the knife on Monday after tearing a ligament.
Nkunku was making his first start after returning from a knee injury which saw him miss three months including France's World Cup run in Qatar.
"I worry that we've lost Cristo for a few days again – that's what it looks like," Rose told broadcaster DAZN after the loss.
"He noticed something in his muscle in a sprint."
Despite playing just 18 of Leipzig's 23 Bundesliga matches, some off the bench, Nkunku's 12 goals make him their top goalscorer this season and joint second in the league.