Sydney, Australia , 12 January 2020 | Glenn Cullen (AAP)

He lost to Rafael Nadal but Alex de Minaur may have won over a few doubters.

Lauded as perhaps the quickest player on tour, his speedwork was again evident in a tight ATP Cup loss to the world No.1.

As was his regular capacity to dig deep.

But concerns that he doesn’t have the weapons to trouble the best of the best will need to be re-examined as the 20 year-old out hit Nadal for a significant proportion of the match.

He finished with 32 winners in the first two sets as he ripped unreturnable shots off both wings.

“I know I’ve got this level. I mean, I’m showing it,” De Minaur said after the loss.

“It’s time for me to get in that mindset more often, in the mindset where I’m believing that I can take it to anyone.

“In that match, that’s how I felt. I felt like I was playing my game and I was doing it my way. Didn’t matter what was happening. I was going to commit to my game plan and keep going for my shots and keep backing myself.”

Australian captain Lleyton Hewitt, himself known as more of a counter-puncher than strike-first player during his lengthy career, liked what he saw.

“I thought Demon for two sets was unreal. He took it to Rafa, probably the better player for nearly the full two sets until he got broken there at the end of the second,” he said.

“But Rafa, some of the shots he came up with when he was under pressure and backed himself, that’s why he’s one of the greatest ever.

Hewitt also made it clear there was still plenty more work to be done.

“This is only best of three sets,” he said.

“To be able to do that with five sets against Rafa, that’s where you’ve got to get to to win the slams.”