The Pole talks about how his serve can improve and how he has improved since his last Grand Slam quarterfinal.
Back spasms forced Elina Svitolina out of the AO fourth round in pain, but she takes pride in her nation's performance.
Late finishes down under are part of a larger problem in pro tennis.
"It's not a match that I thought I lost physically," Aussie No. 1 said after a four hour, 14-minute AO loss to Andrey Rublev.
Marta Kostyuk reached her first major quarterfinal, and two other Ukrainian women could join her.
The American picked up his first Top-10 win at a major - and set a date with Novak Djokovic in the quarterfinals.
World No. 1 sees two main reasons for her stunning AO upset.
