MELBOURNE (Reuters) – Sixth seed Stefanos Tsitsipas has advanced to the third round of the Open after his German opponent Philipp Kohlschreiber withdrew due to injury, organizers said on Wednesday.

ATP Finals champion Tsitsipas, 21, will either Canadian 32nd seed Milos Raonic or Cristian Garin of Chile in the third round, having never faced either opponent before.

“Unfortunately Philipp Kohlschreiber has withdrawn from his #AusOpen match vs Stefanos Tsitsipas due to a muscle strain,” the Australian Open said on Twitter.

Tsitsipas, who last defeated on his way to the Melbourne Park semi-finals, had won both his previous meetings against No. 79 Kohlschreiber.

The Greek is rated by many as the most likely to break the three-year grip Rafa Nadal, Novak Djokovic and Federer have on the Grand Slam titles.

(Reporting by Sudipto Ganguly; editing by Peter Rutherford)