Switzerland's Roger Federer celebrates after his match against Hungary's Marton Fucsovics during the Australian Open in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Kai Pfaffenbach

Switzerland's Roger Federer serves during his match against Hungary's Marton Fucsovics during the Australian Open in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Kim Hong-Ji

Switzerland's Roger Federer in action during his match against Hungary's Marton Fucsovics during the Australian Open in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Kai Pfaffenbach

Switzerland's Roger Federer in action during his match against Hungary's Marton Fucsovics during the Australian Open in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Issei Kato

Switzerland's Roger Federer in action during his match against Hungary's Marton Fucsovics during the Australian Open in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Issei Kato

Switzerland's Roger Federer and Hungary's Marton Fucsovics talk after the Australian Open match in Fourth Round at Melbourne Park, Melbourne, Australia, January 26, 2020. Federer regained control after a slow start against Hungarian Marton Fucsovics to march into the quarter-finals of the Australian Open with a 4-6 6-1 6-2 6-2 win on a chilly evening at the Rod Laver Arena on Sunday. REUTERS/Edgar Su