While Sinner has the upper-hand on hard and clay, he has never defeated Djokovic on grass. And we have already seen the world No 1 on the receiving end of an almighty reprieve this year, given his two-set deficit to Grigor Dimitrov in the fourth round, before the Bulgarian had to agonisingly retire.

Novak Djokovic canceled his afternoon practice session at Wimbledon on Thursday, a day after the seven-time champion had a "nasty" fall moments before clinching his quarterfinal victory.

Novak Djokovic has missed training at Wimbledon ahead of his semi-final on Friday against Jannik Sinner, raising fresh injury fears following his fall in Wednesday’s quarter-final.