Is Novak the clear favourite? 

It’s the question that everyone wants to know. He looks incredible, last year was monumental at his age, to be that great still. Maybe we’re not sure about his wrist and if he’s 100% right now but that happened the last two years. He still won both years despite perceived injuries. People think he’ll be OK but I don’t know where he is physically. Technically he’s the best player I’ve seen, mentally, physically. Unless you have the real belief in your head that you can beat him, you’ve got no chance at all. A few players can rise to the occasion such as Alcaraz at Wimbledon but few have. He’s won ten Australian Opens and the law of averages would say someone at some point will win another one. But we said the same about Rafa at the French so who knows what will happen. 

Boris Becker coaching Holger Rune: 

Boris will have a different perspective about life in general and his coaching methods. He’s got a young player who needs to take that next step to be a Grand Slam champion. If Rune listens to Boris and Boris understands Rune, it could be a great partnership and I’m optimistic it will be good for tennis. As a rival and friend, to see him back on the tennis scene, it makes me feel good. I was very happy to see that. 

Has Zverev’s development stalled? 

If you go back a year and a half, he was on the precipice of maybe beating Nadal at the French Open. It looked like he believed he could win that which was incredible considering Rafa’s success at the French. I give him credit to get back in the mix following his injury. Yes, Alcaraz has gone past him, Rune and Sinner have too. But Zverev is right in the mix and I see improvement in his game. Knowing how much he wants to win a Major, it’s not going to be easy but he’s put himself in a position to do well and I think he can go far. 

There are several players in the men’s game like Dimitrov, Tsitsipas, Zverev who have shown potential but never one a Slam. Why have they not been able to do this? 

I think they’re Grand Slam contesters but they’re not Grand Slam winners. Roger, Rafa, Novak have just been better than everyone. Alcaraz is a hopeful sign for our sport I think as he can do everything and he’s very skilled at every part of his game. Younger and older players will look at him and think they need to do more. There’s a danger he’s already blown past Tsitsipas and Zverev. I think Dimitrov has improved more than any other player in the last year. He had some injuries and confidence struggles but he’s playing as well as anyone. It would be great to see him have a real run and breakthrough. That would be exciting to see, someone who did it the hard way and came through the other side. 

The strength of the US players right now: 

I think Ben Shelton will mean there will be less pressure on Taylor Fritz. To me Shelton has the best chance of winning Majors. He can if he continues to develop. Tiafoe was expecting to make the next step after that great US Open but lost to Shelton., Fritz hits the balls as hard as anyone on the Tour and is a hard worker and top ten player. To go the next step though, athletically some guys are so great. That’s where I think Tiafoe and Fritz struggle a little bit. I think Korda has an upside and can do great things. Tommy Paul is a great kid and has struggled recently but has a semi-final next week. The Shelton, Korda, Tiafoe, Fritz  

How can Coco Gauff take the next step to one day be world no.1?  

I see it like Alcaraz against the bigger hitters. She is not as big as Rybakina, Sabalenka, Swiatek but she’s extremely athletic the way Alcaraz is. I expect her to win more Majors. It can be done. She is in a good places mentally, added pieces to her team recently like Brad Gilbert who knows what it takes. I expect big things from her and she’s still young. Over the next ten years I would be surprised if she doesn’t win a bunch of Majors. Soon there will be more younger players to add to the mix. I think Swiatek has done a great job at keeping up her level for so long now so it will be really hard for Coco to et close to her ranking any time soon though. 

Comments on Andy Murray ahead of potentially his final Australian Open: 

It’s hard for Andy to continue at no.45 in the world as this is one of the greatest players of the last 15 years. It’s also going to be hard for him to retire as he loves the game. He thinks he can get one big run or a big chance. Maybe playing Novak or Rafa in the semis of a Major. He’s been in 11 Grand Slam finals, Andy Murray. At the end of my career, it was hard to accept you weren’t the player you once were. Deep down, I think he thinks that he can still do it. Like Rafa, who knows if the body can hold up even if he did start playing at the level he needs to. It’s rare you ever go out how you want to. Pete Sampras won the US Open at 31 years old and decided it was the perfect time to go at 14 Majors and thought no-one would ever catch him. I wonder if he looks back now and thinks maybe he should’ve kept playing as he didn’t think these other guys would go on to get 20, 22, 25 Majors. You start to second guess when the best time to go is.  

John McEnroe is an expert for Warner Bros. Discovery Sports' coverage of the Australian Open in Europe. Coverage starts on discovery+, Eurosport and Eurosport App from Sunday 14 January.