Rafael Nadal has said he is wary of "dangerous" Frances Tiafoe, after the American youngster set up an Australian Open quarter-final clash with the Spanish second seed.
Nadal booked his 11th quarter-final appearance at Melbourne Park with a ruthless 6-0, 6-1, 7-6 win over Tomas Berdych, allaying doubts about his fitness in the process.
Next up in the Spaniard's firing line is 21-year-old Tiafoe, who celebrated his birthday in style by reaching his first grand slam quarter-final after an impressive 7-5, 7-6. 6-7, 7-5 win over Bulgarian 20th seed Grigor Dimitrov.
"It's going to be the first time that we play each other. Yeah, he's playing great," he said of 39th-ranked Tiafoe, who created one of the shocks of the tournament by knocking out fifth seed Kevin Anderson in the first round.
"I know him, of course. He's been on the tour for a while. He's young. When you have younger players coming, they have always more attention."
Tiafoe, whose best previous grand slam result was reaching the third round of Wimbledon last year, warmed up for Melbourne by partnering Serena Williams in the mixed teams Hopman Cup.
"He's a very dynamic player, aggressive one. Of course, he's dangerous," said Nadal. "He's in the quarter-finals. He won great matches during the whole event. He's super quick. And he's able to change directions fast.
"He goes to the net fast. He has a huge forehand, good serve. So let's see."