Canada's Felix Auger-Aliassime withdrew from the Erste Bank Open on Wednesday due to an ankle injury.
The 19-year-old was scheduled to open the tournament against Russia's Andrey Rublev in the Round of 32, but said he incurred the injury while practising on Tuesday.
"Sadly I won’t be able to play my first round match at the@ErsteBankOpen today," Auger-Aliassime wrote on Twitter. "I unfortunately hurt my left ankle at practice yesterday. Will keep you updated on how my recovery is going. Thanks everyone for your continuous support. Danke Wien. See you next time."
At No. 18, Auger-Aliassime is currently Canada's top-ranked player on the ATP Tour.
Dating back to his loss against fellow Canadian Denis Shapovalov in the Round of 128 at the US Open, Auger-Aliassime has lost four of his past six matches.