Johanna Konta's new coach Wim Fissette says he is convinced the British number one can win a Grand Slam.
The 25-year-old plays Russian Ekaterina Makarova in the Australian Open last 16 on Monday at 02:00 GMT.
The winner could face 22-time Grand Slam champion Serena Williams in the quarter-finals.
"I started working with her because I really believe she can [win a Grand Slam] if she keeps getting better like this," said Fissette.
"She has the game. It's always great to see a girl who has a very big first serve, a very big second serve - which girl can do that?