Jannik Sinner has cancelled his afternoon training session at Wimbledon but the world No.1 is still optimistic he can play his quarter-final tomorrow. The Italian fell and injured his elbow during his Monday night win over Grigor Dimitrov. The US Open champion underwent an MRI scan today and had booked a 4pm practice time at Aorangi Park. Speaking after his win over Dimitrov, Sinner said in Italian: "If I don't have any problems, I will hit some balls tomorrow."

But the three-time Grand Slam champion did not show for the session and has not been seen at the All England Club today. Sinner, 23, is scheduled to face big-serving American Ben Shelton in the second match on Court One on Wednesday.

And sources close to his camp claim he is still determined to play the quarter-final and is just resting today as a precaution.

Sinner took painkillers during his fourth-round win and said: "It happened very early in the first game. It was quite an unfortunate fall. Checked the videos a little bit, and it didn't seem tough one, but I still felt it quite a lot, especially serve and forehand. I could feel it. So let's see. Tomorrow we are going to check to see how it is, and then we see."

Sinner fired two members of his team - fitness coach Marco Panichi and physiotherapist Ulises Badio - on the eve of Wimbledon without explanation. The two were replacements for his former physio and fitness instructor who were sacked after he tested positive for a banned substance last year.

"They have good ATP physios, in any case," said Sinner. "The doctor's good. As I said, tomorrow we are going to check with MRI to see if there's something serious, and then we try to adjust it."