Jannik Sinner caught swearing at coach at Paris Masters as partnership remains uncertain

Frustrations spilt over for Jannik Sinner on Friday night as the world No. 2 was caught swearing at his team mid-match. Sinner took on Ben Shelton in the quarter-finals of the Paris Masters, and looked well on his way to victory when he took the first set and then went 3-1 up in the second.

But the Italian started muttering at his box and was immediately broken to love. He then marched over to them and asked why they were "f****** sitting". Sinner recovered and sealed a 6-3 6-3 victory. However, his future with coach Darren Cahill remains unclear, as Cahill is expected to leave his team at the end of the season.

Sinner is through to the semi-finals of the Paris Masters for the first time in his career, but he hasn't looked at his best this week. The world No. 2 appeared to be struggling against Francisco Cerundolo on Thursday and said: "It's clear I'm not at 100 per cent."

It was a similar story against Shelton in Friday's quarter-final, as Sinner looked rocky at times, but still managed to come through in straight sets.

The four-time Major winner wasn't happy with his team when he took an early break in the second set, asking them to cheer more. Sinner played a sloppy game and looked at his box, waving his arms.

"You don't often see that from Sinner, I think he was just asking his team to stand up, they found that quite amusing. Darren Cahill staying firmly seated," Adam Fielder said on commentary.

Shelton broke straight back, and Sinner confronted his coaches as he went to grab his towel after the changeover. "I got a break and you are f****** sitting," he told Cahill and co. They responded with cheers of "Forza".

Sinner managed to break again at the end of the second set, with Shelton giving it away on a double fault. It allowed the Italian to serve for the match, and he obliged, finishing off with a winner to reach the last four.

The 24-year-old might want to avoid crossing any lines with Cahill, as he's hoping to convince the renowned Australian tennis coach to stay in his team. At the start of the season, Cahill confirmed that this would be his last year working with Sinner.

However, he seemed to U-turn on his decision after Sinner won Wimbledon. Asked whether he'd reconsider, Cahill said: "I don't want to answer this. You know what, you just need to ask Jannik that."

Speaking during the Italian portion of his press conference a few minutes later, Sinner joked: "It depends if I want to tell the truth or not. We made a bet before the final, I told him that if I won, I could choose whether he could stay or not at the end of the year. Now the choice is mine!"

The 2025 season is now almost over, and Sinner and Cahill have yet to discuss their future. Ahead of last week's Vienna Open, the world No. 2 told ATP Media: "We haven't talked yet, to be honest. We said we are going to finish the year, and then we might ask him for a long chat, trying to convince him.

"But in any case, if he stays or not, he has been an amazing person and obviously a coach for me to hold the whole team together in the tough moments.

"He is like a second father to me, so I'm happy to have him here. It's a huge privilege to work with him. We aim for something very positive [for him to stay], and I will need a lot of hope for that."