As John McEnroe was signing off of the ESPN broadcast of the Australian Open men’s final on Sunday, he issued an encouraging directive to America’s top young men’s tennis stars.

“Come on, you young Americans, you Ben Sheltons, we need you to step up,” McEnroe declared.

McEnroe believes Shelton, the 21-year-old former NCAA champion who reached the U.S. Open semifinals last year, has what it takes to win a Grand Slam title — if not in 2024 then down the road.

But Shelton and his fellow Americans face huge roadblocks when it comes to winning majors — and they all seem to come from Europe.

With Jannik Sinner’s five-set victory over Daniil Medvedev Sunday, European men have now won 77 of the last 78 major singles titles dating to Wimbledon in 2004. Juan Martin del Potro of Argentina at the 2009 U.S. Open is the only non-European during that time to hoist a Slam trophy.

Of course, during most of that span, three European men have dominated men’s tennis. Serbia’s Novak Djokovic (24), Spain’s Rafael Nadal (22) and Switzerland’s Roger Federer (20) have combined to win 66 majors….and counting.

Britain’s Andy Murray and Switzerland’s Stan Wawrinka each won three majors during that span, while more recently Spain’s Carlos Alcaraz has won two, including last year’s Wimbledon final in which he beat Djokovic.

And now with the emergence of the 22-year-old Sinner as a major champion, it appears he and Alcaraz, 20, will be featured in the main rivalry of the next decade.

“I think we’re going to see these young guys push each other and Medvedev is going to be in the mix as well in the same way we saw the ‘Big 3’ push each other over the years,” Patrick McEnroe said on ESPN. “I think with Alcaraz and now with this man Sinner, you’ve got a couple of guys who are going to elevate the game and continue to push it forward. But you know what, Novak is not done just yet.”

So where does all of this leave American tennis?

Andy Roddick remains the last American man to win a major title at the 2003 U.S. Open — more than 20 years ago.

Still, Martin Blackman, the General Manager of USTA Player Development, believes there is reason for optimism.

“From a process, development and performance perspective our top men have definitely stepped up and we are excited about 2024, with twelve players in the Top 100, all of whom have their best tennis ahead of them,” Blackman wrote in an email.

Blackman pointed out that in the last two years Americans Shelton, Tommy Paul and Frances Tiafoe reached the semifinals of majors, and that the U.S. has more players (7) ranked in the Top 50 than any other country: No. 9 Taylor Fritz, No. 14 Tiafoe, No. 15 Paul, No. 16 Shelton, No. 32 Chris Eubanks, No. 33 Sebastian Korda and No. 48 Mackenzie McDonald. Blackman is hopeful that Jenson Brooksby and Reilly Opelka “will be returning to competition soon.”

“I think its very realistic that an American man will win a Slam this year, but the focus is always on the process, always on getting better which is why Team USA is seeing the best results we’ve had in 25 years, because we’ve been consistent in that focus,” Blackman added.

A huge stumbling block for the American men is that in order to win a Slam, or even get to the final, any one of them likely has to beat 2-3 of the Djokovic/Medvedev/Alcaraz/Sinner/Alexander Zverev/Stefanos Tsitsipas crowd. A huge ask.

Fritz, for example, lost in four sets to Djokovic in the Australian Open semis to fall to 0-9 against the Serb. Even if he had somehow upset the world No. 1, he would have gotten a red-hot Sinner in the semifinals and then Medvedev in the final.

“Yes, Sinner, Medvedev, of course Djokovic and the other top guys in the Top 10 are going to make it hard for everyone, but so will our guys,” Blackman said. “And our top men are notching more and more top-5 wins every year; having the fitness, mental toughness and belief to beat them in a three out of five Grand Slam will be a great challenge, but they can do it.”

On the women’s side, of course, the Americans have done much better — and not just Serena and Venus Williams.

Coco Gauff won the U.S. Open last fall, a year after Serena retired following the event, and followed it up with a semifinal run in Melbourne.

“Coco’s win at the U.S. Open is an inspiration at every level of the game, with a ripple effect throughout the entire ecosystem,” Blackman said.

“Every time an American wins a Grand Slam it’s an inspiration for juniors, league players, public park players and definitely our pro players who are supporting each other more than ever due to the Team USA initiative that they experienced in the juniors.

“That’s why its so important to have a pipeline full of great players, so that we can maintain the momentum of having great American pro players that represent Team USA and are willing to give back to grow the game. This is an incredibly generous generation of top Americans and its very encouraging to see how responsive they are to giving back when asked.

Blackman pointed out that in the 13 years before 2008, Americans won two Grand Slam Junior titles, but since 2009 the U.S. has won 22. Blackman attributed that to the “Team USA Junior Pathway that was driven by a three-way partnership between USTA Player Development, the USTA Sections and our amazing USTA Sections from 2009-2019.”

There is reason for optimism, but the European men continue to dominate at the highest levels of the game.

So, come on you young Americans, you Ben Sheltons, you need to step up.