Sampras hailed the Australian as one to watch but he became stuck between two great eras of the game.
Lleyton Hewitt: the one they left behind
Watching Lleyton Hewitt's first-round loss at Wimbledon to Jo-Wilfried Tsonga was like undergoing a prolonged double-take.
First, even though he has not retired, Hewitt has so quietly settled himself on the periphery of the scene - and Hewitt never did anything quietly - that it was a surprise to see him on TV, still playing.
Then, to register his presence and do so in a match against Tsonga was to be lulled into believing instantly this was a big match: the former world No 1 and Wimbledon champion against the current fifth seed, on court No 1 at Wimbledon.
Except that neither was it a big match in actual battle, nor really on paper anymore; Hewitt is currently ranked 202.
And finally, there was Hewitt himself, because this was not really Hewitt. It was Hewitt because he was still scrambling around like the very existence of the planet depended on whether a tennis ball bounced a second time, baseball cap backwards, still looking like the whole world was on the wrong side of the bed for him.
But this was Hewitt doused. He still did not want that ball to bounce again, but his legs could not do much about that anymore and his brain, not wanting to accept it, just had to.
And as he went down in straight sets, it seemed reasonable to question the double-take: whatever happened to Lleyton Hewitt?
The easy answer is Roger Federer; they are contemporaries, Hewitt older by only five months. But that would be to forget just how ferocious and successful Hewitt once was.
As he won the 2001 US Open and following Wimbledon, and successive Master's Cup titles, Hewitt was scripting a new golden age.
He remained top of the world rankings for 75 weeks from November 2001 to April 2003, the longest unbroken reign since Pete Sampras's 102-week run from April 1996, and bettered only by Federer since (not Rafael Nadal, not Andre Agassi, not Gustavo Kuerten, not Andy Roddick, not Marat Safin, and even Novak Djokovic is a good 20 weeks short right now).
He was that dominant.
At the time he was carving out a new style, in which power, attrition and athleticism were the fundamentals.
He repeatedly did crazy things from the baseline, chasing down balls no one else could and being more precise and powerful in his groundstrokes than seemed imaginable.
All this is pretty embedded now but it was not then. When he won Wimbledon a decade ago, it still felt novel, maybe even a little wrong for a baseliner to be doing so (Agassi a decade earlier was the last). It was not great to watch but it had to be admired for its rigour and refusal to yield, and for just how different it looked to the game we had been watching until then.
It was limited in a way, based around an undying spirit for retrieval but that just made his dominance all the more remarkable. More than Federer, who is an aberration, it is Hewitt's game which the modern game appears to have evolved from.
It made sense - in the kind of shallow way that advertising campaigns can - that Hewitt, along with Safin, stood at the centre of eight players chosen by the ATP in its repositioning in 2000 in the famous "New Balls Please" campaign. (Federer was also there.)
But the words of Sampras after the 2001 US Open final carried greater prophetic weight. Sampras had not lost as much as he had suddenly become obsolete over three sets.
"The kid is so quick it's unbelievable. I wish I had some of those legs for this old guy.
"I lost to a great champion. You're going to see this Lleyton Hewitt guy for the next 10 years like you saw me."
Soon after Hewitt would become the youngest world No 1, at 20 years and nine months, and if Sampras sounded unusually hyperbolic - and he did not sound as in awe after the more seminal defeat to Federer at Wimbledon that year - it was only because most of tennis felt that way.
That it did not turn out that way has much to do with Hewitt running himself into the ground.
His knees and hips betrayed him first, requiring major surgeries, and then hand, wrist and back problems hurt him.
In February this year he had screws inserted in his left big toe, which left him relearning how to walk. He says he has played the last two years on painkillers; his manager says the last five have not been pain-free.
And so, instead of creating his own golden age, he gently fell in between two, a little less golden for it.