The future has arrived on the WTA and ATP tours

Neither Daniil Medvedev nor Coco Gauff will finish No. 1 for the year or win a Grand Slam singles title. Unlike Medvedev, Gauff won't even get to play in her year-end championships, which is restricted to the eight top-ranked singles players.

But make no mistake, Gauff and Medvedev are on their way to setting the terms of the conversation in tennis in 2020. It's something that few would have predicted as recently as mid-year, yet here they are.

On Sunday in Linz, Austria, 15-year-old sensation Gauff became the youngest player to win a WTA title in 15 years. At the same time in Shanghai, Medvedev won his third title in six consecutive finals, this at a high-value Masters 1000 tournament.

Gauff might have been speaking for the accomplishments of both when she told reporters after her win: "This was definitely not on the calendar at the beginning of the year."

On the face of it, the two young players have little in common, even age-wise. At 23, Medvedev is a regular Methuselah compared to Gauff, if not 38-year-old Roger Federer. Also, Medvedev has been a relatively slow starter in that first wave of "Next Gen" players promoted by the ATP as potential successors to the Big Four. By contrast, Gauff bolted to "sensation" status with a six-match run that landed her in the fourth-round at Wimbledon. It took the eventual champion, Simona Halep, to bring her to a halt.

The tangible, quantifiable contrasts may be marked, but Gauff and Medvedev have more in common than it appears.

Both of them were subject to a reality check at the US Open, where Rafael Nadal disarmed the arsenal that powered Medvedev through his torrid summer. Defending US Open champion Naomi Osaka gave Gauff a harsh introduction to the school of hard knocks before consoling her with a sisterly embrace in the third round of the US Open.

Gauff and Medvedev have displayed a heartening measure of a rare commodity in young players, consistency. Medvedev is 29-3 over his last six tournaments. Gauff, who started the year in minor league events with a ranking of 684, is up to No. 71 on the strength of her 18-6 WTA main tour record (she was 29-14 overall).

Poise appears to be ingrained in both Gauff and Medvedev, although the Russian star has shown an appetite for occasionally peeling off his game face and squabbling with certain rivals as well as fans. Perhaps most important, Gauff and Medvedev are versatile players whose games are built on a foundation of superb athleticism.

"I'm not going to say she will win 25 Grand Slam titles," Robert Lansdorp, the coach who developed other prodigies, including Pete Sampras, Tracy Austin and Lindsay Davenport, told ESPN.com. "But Gauff has all the qualities that make a great, great player. The fact that she loves to fight, that she has that discipline, concentration and focus -- those are huge pluses at a time when so many of the other WTA players just can't find the consistency to win steadily."

Lansdrop said he would like to see Gauff hit "a little harder," which she almost certainly will as she grows into a fully mature player. But the architect of some of the most airtight games tennis has ever seen believes that Gauff's anticipation and foot speed more than compensate for what she may lack in firepower, now and in the future.

"Her speed is a great advantage," Lansdorp said. "Serena [Williams] had more power when she came on the scene, but Gauff is already a great defensive player. She's so fast that it's tough to get a winner against her, and she already has that talent for going from defense to offense very quickly."

Gauff also has that champion's instinct for fully exploiting opportunities, including unexpected ones. Her win in Linz was just the third in WTA annals by a "lucky loser," or player who lost in the qualifying but got into the main draw as a last-minute replacement. "My dad told me when I got in, before the first main-draw match, he said: 'You can't lose twice in the same tournament!' Gauff told reporters. "I guess he was right."

Gauff has had to juggle her burgeoning career with the WTA rulebook, which restricts the number of tournaments in which a player under the age of 18 can participate. She is eligible to play 14 events before she turns 16 (next March). She has already played 12, which leaves her somewhat handcuffed in the new tennis year.

"I understand the [age eligiblity] rule completely, that they [the WTA] want the young players not to play too much," said Federer, whose Team 8 boutique management firm represents Gauff. "I've told the WTA they should loosen up the rules. I loved seeing [Martina] Hingis doing what she did at a young age."

Hingis, who was grandfathered in as an unrestricted player when the age eligibility rules were passed in 1993, won the Australian Open at 16 years and three months, then went on to win Wimbledon as well as the US Open to set a new high-water mark for prodigies.

Working with no such restrictions, Medvedev compiled a streak of six consecutive finals. That's fifth-best among active players, right behind the usual Big Four suspects. The run has lifted him to the No. 4 ranking, and he has a solid shot at displacing Federer at No. 3 before the end of the year.

Medvedev leads the the ATP Tour in four significant categories, including most match wins (59), most match wins at Masters 1000 tournaments (22) and most finals (a grand total of nine, with four titles won). Medvedev is now firmly established as the player most likely to break the Grand Slam title monopoly of the Big Four, who have swept the last 12 majors, and 54 of the last 59 dating back to 2005.

"It's something outrageous what I've done in the last few months," Medvedev said on the court in Shanghai after his win. "I wouldn't have believed it."

Most likely, his chief Next Gen rivals also would have been hard pressed to believe what he's done. This edition of Shanghai may be remembered as the tipping point in the struggle to unseat the aging members of the Big Four, three of whom claimed every Shanghai title in the past decade, prompting Medvedev to remark, "It's really special to have my photograph in the [stadium] corridor for the next some years."

The Next Gen crew ran amok in Shanghai. In a pair of quarterfinals that may resonate for a long time, Stefanos Tsitsipas logged a hard-fought quarterfinal win over top seed Novak Djokovic. Alexander Zverev, long the poster boy for his generation, eliminated Roger Federer. It ultimately left Medvedev and No. 6 Zverev poised for a shootout in an ATP final featuring the youngest duo in a decade.

The finalists came in with a fairly deep but distinctly one-sided history, Zverev having won all four previous matches. "I think I just became a better player than I was when I played him before," Medvedev told reporters after 6-4, 6-1 blowout. He added, "Something clicked in my game in the USA [at the start of the hard-court season]. I don't know why."

Medvedev has had to deal with a luxurious problem that many versatile players -- perhaps including Gauff -- face early in their careers. They need to understand which tools to choose for specific jobs, and how and when to use them.

"I started to understand even more about my game [this summer]," Medvedev said. "About my serve, about my volley, about everything, like kind of what do I have to do, when?"

Medvedev didn't lose a set to either of his generational rivals in back-to-back wins in Shanghai. Zverev and Tsitsipas may still halt the Medvedev juggernaut. The Next Gen "Big Three" can argue things out at one more Masters 1000 event (Paris), as well as the ATP World Tour Finals. But one thing is clear: If the Next Gen stars continue to perform as they did in Shanghai, they will reshape the landscape in men's tennis for the first time in a decade-and-a-half.

"Everybody is talking that they need new guys, something new, so I gave them something new," Medvedev said. He added, "I don't celebrate my wins. I just stay calm, I do my job. Boom, done."

Medvedev's job is unfinished, Gauff's barely begun. But be prepared for more "boom" coming from both of them.