Vienna - Ski jump World Cup winner Gregor Schlierenzauer was to undergo surgery Thursday after injuring his right knee while testing skis on Wednesday.

The 19-year-old Austrian is believed to have torn a ligament after twisting following a landing in fresh snow in Ramsau, the Austrian news agency APA reported.

Schlierenzauer clinched the World Cup earlier this month and last week claimed a record 13 wins in a season while breaking the 2,000-points barrier. (dpa)