Roger Federer has heaped praise on Alexander Zverev after beating the German in three sets in his second round robin match at the ATP World Tour Finals underway in London.

The Swiss ace booked a place in the last four with his second straight win and looks on course to win his seventh ATP Finals title. Federer however chose to focus on the young talent on the ATP Tour namely Zverev, Denis Shapovalov and Nick Kyrgios and believes the trio are on the path to emulating members of the current big four Rafael Nadal, Andy Murray and Novak Djokovic.

Zverev is much ahead in the learning curve compared to the other two mentioned by the Swiss tennis legend as he has already tasted success at a high level this year. The 20-year-old German won two Masters Series titles in 2017 — Rome and Montreal — and looks favourite to end the year as the world number three.

Kyrgios and Shapovalov, on the other hand, are ranked 21 and 51 respectively but have shown that they have the talent to be future stars of the game. They have both had relatively successful 2017 campaigns, but will be looking to progress further in 2018.

The former has won three ATP titles thus far and has been branded as a future number one, but his temperament remains in question owing to a number of on-court and off-court transgressions in recent years.

The latter, at 18, is still in the infancy of his career after breaking into the top-50 for the first time in his career. He is yet to win an ATP title, but he made the round of 16 in the US Open and made it to the last four of the Montreal Masters showing that he has potential to challenge for top honours in the future.

Federer is confident that the trio have the talent to emulate the current stars of the game owing to their ability to plan long-term and see the bigger picture when they get into their prime.

"I like what I'm seeing with Sascha," Federer said about Zverev after the match, as quoted by the Metro. "I see somebody who is working towards the future.

"I think, yes, of course it's really important right now to have success. He had that with two massive wins in Rome and Montreal. I mean, that's going to protect his season anyways. The rest sort of is all a bonus.

"What I like to see is I feel like they're working towards how he could be playing when he's 23, 24 years old in terms of fitness, planning, organisation, all these things. I think that's nice to see," the Swiss ace explained.

Denis Shapovalov
18-year-old Denis Shapovalov broke into the top-50 in 2017 Getty

"Now, the future? The thing is it seems like they need a bit more time, the young guys in general, to break through these days. Even though I'm really happy to see that there are the likes of Shapovalov or Nick, now also Zverev, making the move early, like what Rafa and Andy did, Novak, Lleyton, all these guys. They were such great teenagers. I do see a great upside from all these three guys," the world number two added.