“I just think the next couple of years are going to be so crucial for him,” Federer said while calling for the Australian public to also cut Bernard Tomic some slack.

Federer has been a Kyrgios fan since the pair practised together in Switzerland before the Canberran’s breakout run to the Wimbledon quarter-finals in 2014.

“I was already unbelievably impressed at his sheer power, his talent, his potential,” said Federer.

“It goes way back. He’s enjoyable to watch. I know some people might not like it [but] I like it. He’s got a lot of personality.

“[He] might take it [too] far to some extent, but I think he’s a great player.

“He’s got sick power, and it’s going to take him a long way.”

Provided Kyrgios – already a two-time grand slam quarter-finalist but set to drop outside the world’s top 40 after after his third-round Australian Open exit – realises “how important the next couple of years are” and knuckles down.

“Otherwise the train leaves the station and you’re maybe not on it,” Federer said.

“It would be a pity to waste talent and all that, even more so in this day and age because I feel talent brought you further back in the day.

“Just talking about a guy who has talent and potential, I can’t hear it anymore.

“Too many guys have talent. Too many guys are working hard. I don’t believe in that very much anymore.”

A racquet-smashing tantrum thrower himself early in his grand career, Federer empathises with Kyrgios, whose image has taken a battering over the past six months.

“It just takes time for people to get to know you. I had the same thing,” Federer said.

“I felt very misunderstood many times when I was younger.

“I felt like I had to put in a lot of work with the press so they first knew who I was so they could relay the messages to the public, the broader public, the right way.

“So in a way I always feel like it’s really interesting and nice to see a youngster grow up in the public eye.

“But then at the same time, you also have the negatives. He’s fighting that a little bit.

“But he’s doing okay now, better now.

“He needs to, obviously, for what happened last year.”

Federer and arch-rival Novak Djokovic are setting themselves for a dream Australian Open semi-final at Melbourne Park tomorrow night after sweeping into the last four with a pair of straight-sets wins.

Djokovic wasn’t at his dominant best against Kei Nishikori but still took out Japan’s seventh seed 6-3 6-2 6-4 after Federer crushed sixth-seeded Czech Tomas Berdych 7-6 (7-4) 6-2 6-4 yesterday to progress to an amazing 39th grand slam semi-final.

Open fans will be treated to the 45th instalment of an epic career series, with Federer and Djokovic locked at 22 wins apiece.

Djokovic came out on top in the last three grand slam finals they’ve contested – at Wimbledon in 2014 and 2015 and in the US Open decider in September.

While he’s dominated Murray in three Australian Open finals, Djokovic credits his decade-long rivalries with Federer and Rafael Nadal, whom the Serb leads 24-23 overall, for transforming him into a 10-times major winner.

“Honestly, I played so many times against both of these guys. At one stage, I lost count of how many times I played,” Djokovic said.

“I’ve played these guys so many different occasions. I’ve battled them for biggest title in sport.

“These two guys made me the player also I am today. I think these rivalries have allowed me to grow and to evolve and to get strong and tough and understand what it takes to be on the level that they are on.

“I mean, they’ve been dominating the tennis before Murray and myself came along.

“It’s always a great challenge. With Roger, you don’t need to spend words on his achievements and what he’s done for this sport.

“He’s a great champion, someone I have lots of respect for and we’re going to have a good match, I’m sure.”

-AAP