MELBOURNE, AUSTRALIA - JANUARY 07: Stan Wawrinka of Switzerland hits a forehand during a practice session ahead of the 2018 Australian Open at Melbourne Park on January 7, 2018 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images)
MELBOURNE, AUSTRALIA - JANUARY 07: Stan Wawrinka of Switzerland hits a forehand during a practice session ahead of the 2018 Australian Open at Melbourne Park on January 7, 2018 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images)