The Champions League quarterfinals are set to begin next week, with Bundesliga’s Bayern Munich looking to defend their title. However, their quest for a second straight Champions League trophy will be tougher without leading striker Robert Lewandowski.

Lewandowski, who has scored 42 goals in 36 matches for Bayern Munich this term, will miss their quarterfinal tie with Paris Saint-Germain after injuring the ligaments in his knee. In a statement, the team announced that the 32-year-old will be out for around four weeks.

Aside from their quarterfinal draw against PSG, the same team they defeated in the Champions League Final last season, Robert Lewandowski will also miss Bayern’s match against RP Leipzig in the Bundesliga. He suffered the injury while playing for the Polish national team during Poland’s 3-0 win over Andorra in the World Cup qualifiers, ruling him out for their next match against England. The initial timeline for the injury was 10 days, before it was upgraded to four weeks.

Lewandowski, the reigning FIFA Men’s Player Award and UEFA Men’s Player of the Year Awards winner, could also miss the Champions League semifinals even if his team beats PSG. With their leading scorer out, Bayern would also face a close battle in their domestic league, which they lead by four points with eight games left on their schedule.

However, not having Robert Lewandowski against the French powerhouse will be a tough challenge, especially since PSG is still coming off an inspiring victory over Lionel Messi and FC Barcelona. Without their best player, Bayern Munich will find themselves tested if they are to return to the top once more.