Jannik Sinner says he can only improve in a warning to Novak Djokovic and Carlos Alcaraz after winning the US Open.

Jannik Sinner welcomed the “new generation” taking over men’s tennis after the world No.1 and Carlos Alcaraz shared all the Majors this season – and warned Novak Djokovic and co. he will only improve.

The Australian Open champion, 23, completed the hardcourt double by beating Taylor Fritz to win the US Open title.

Jannik Sinner now has two Grand Slam titles to his name (Image: GETTY)

And after Carlos Alcaraz, 21, won the French Open and Wimbledon, it is the first time since 1993 that all four Majors in the same year have been won by players 23 or younger.

It is also the first tennis season since 2002 that none of the Big Three – Novak Djokovic, Rafa Nadal and Roger Federer – have won a Grand Slam.

“It is a bit different, for sure,” said Sinner. “It’s something new. It’s nice for the sport to see some new champions. Nice to see new rivalries. I feel like the new generation we push each other, trying to improve.

“I always have players and I will always have players who are going to make me a better player, because there are going to be times where they beat me.

“Then you have to try to find a way how to win against certain players. I feel it’s good for the sport to have some new champions.”

Starting in Melbourne in January, Sinner has now won all six finals this season. He is the youngest man to win both hard court Grand Slam titles in the same season.

And he is only third man in Open Era – after Jimmy Connors in 1974 and Guillermo Vilas in 1977 – to win his first two Grand Slam titles in the same year.

And the Italian warned he is only going to get better. “Today we saw that not everything was perfect,” he said “I could have served slightly better, but this makes me realise that the work never stops.

Jannik Sinner defeated Taylor Fritz in straight sets in Sunday’s final (Image: GETTY)

“It’s always a continuous work which, at the end of the day, if you want to be a better player you always have to work, and you have to have these daily routines, accept difficult times on court.

“The work never stops. How can you play better against certain opponents,? How do you work on such shots?

“I was a lot in the gym, because I knew physically I still had to improve and I still have to improve a lot. This is all part of the sacrifices you make for an eventual future. So we will keep working.

“I know that I’m not perfect and I will never be perfect, but we always try to evolve in my game. Then after my career I can say: ‘Okay, I’ve done everything possible to be at 100 per cent.’”

In his courtside interview after beating Fritz in straight sets, Sinner admitted: “The last month has been very difficult because you all know what I went through.”

The world No.1 was cleared to play in New York after a tribunal accepted his two positive tests back in March were caused by a massage by his ex-physio.

Many players – past and present – cast doubt on the process while Nick Kyrgios branded the judgement “ridiculous”.

Asked how the tennis world will react to his second Grand Slam title, the Italian said: “I don’t know. You have to ask all the other players. This, I don’t know. Well, that what I can say is that the general reaction of the players was quite positive, even when things came out.

“Then there have been, of course, some different voices, but this is in everything. This is not only in tennis. This is in other sports and different jobs also. You can’t really do anything about that.

“That’s why you have the people close to you, these are the people who knows what was going on and what I and my team went through because it was not only me; it was the whole situation. I just can talk from my side and from my team’s perspective, and we are all very proud of this achievement.”