World number one Novak Djokovic said Friday he hoped it would not become compulsory for players to be vaccinated against coronavirus and insisted any decision he makes on whether or not to take the vaccine will remain private.
"I am still a supporter of freedom of choice," Djokovic said after reaching the semi-finals of the ATP tournament in Belgrade.
It was in the Serbian capital last summer where Djokovic, as well as a number of other players, tested positive for Covid-19 after organising a controversial exhibition event.
On whether or not he will be vaccinated to guarantee entry to tournaments, 33-year-old Djokovic refused to commit himself.
"I will keep my decision to myself, I think it's a private, intimate thing. I do not want to be labelled as someone who is for or against vaccination," added Djokovic who has expressed his reservations in the past.
"I hope it does not become compulsory."
On court, Djokovic stayed on course for a third Belgrade title with a comfortable 6-1, 6-3 quarter-final win over compatriot Miomir Kecmanovic.
Djokovic, the 2009 and 2011 champion at the event which is played at a venue which carries his name, will face Russia's Aslan Karatsev for a place in the final.
In their first meeting, Djokovic broke his 21-year-old opponent's first service game and repeated the feat for a 5-1 lead in the opener.
His only blip was when he was broken as he served for the match at 5-2 in the second set.
However, it was a brief respite for world number 47 Kecmanovic who handed back the break in the next game allowing the top seed to complete a 75-minute win.
"I think personally I'm feeling very well on court, moving well, hitting the ball well and, of course, enjoying the home court advantage," Djokovic said.
"So I'm really excited to go out in the semi-finals on the court again tomorrow."
Djokovic, who captured an 18th Grand Slam title in Australia in February, opened his clay court campaign in Monaco last week where he suffered a surprise last-16 loss to Britain's Dan Evans.
On Saturday, he will face Russian third seed Karatsev who put out Gianluca Mager of Italy 6-3, 6-4.
Djokovic ended Karatsev's stunning run at the Australian Open in the semi-finals in February where the Russian, then ranked at 114, came through qualifying.
Japan's world number 126 Taro Daniel also booked a last-four place on Friday by beating Argentina's Federico Delbonis 4-6, 6-1, 7-5.
Daniel is the first lucky loser to reach an ATP semi-final this year.
On Saturday, he tackles 10th-ranked Matteo Berrettini, the Italian second seed who knocked out Serb fifth seed Filip Krajinovic 6-4, 6-4.
Daniel has never beaten a top-10 player in four previous attempts.