PARIS • Injury worries clouded Novak Djokovic's hopes of a second French Open title as he said he had suffered neck and shoulder problems during his laboured quarter-final win over Spain's Pablo Carreno Busta on Wednesday.

The 33-year-old top seed walked out onto a chilly Court Philippe Chatrier with the back of his neck taped and he also needed treatment on his upper arm during the match.

It looked as though Carreno Busta was primed to cause an upset when he won the first set, but Djokovic survived to win 4-6, 6-2, 6-3, 6-4 and move into his 10th French Open semi-final today when he will play Greek fifth seed Stefanos Tsitsipas.

"I definitely didn't feel great coming into the court today. Few things happened in the warmup," said the world No. 1, who looked constrained, especially on his trademark backhand early on.

"I had to deal with those physical issues. As the match went on, I felt better, didn't feel as much pain. Especially for set and a half, he was the better player, dictating the play.

"I didn't have much of energy really happening in my legs or movement or game itself."

Asked exactly what the problem was, he said: "I had some neck issues and some shoulder issues. I don't want to get really too much into it. I'm still in the tournament, so I don't want to reveal too much."

It was Carreno Busta who Djokovic was facing in the fourth round of the US Open a month ago when he struck a female line judge in the throat with a ball that he had swatted away in frustration, ending in his disqualification.

The Spaniard accused Djokovic of gamesmanship on Wednesday as he felt the Serb did not have any genuine health issues.

"Each time he is in trouble, he usually does it... " Carreno Busta said. "Every time a match gets complicated, he asks for medical assistance. He has been doing this for a long time."

Djokovic's path to what he hopes will be an 18th Grand Slam title is now blocked by Tsitsipas, who will be dangerous, especially if he is less than 100 per cent fit.

"I expect a really tough, tough match, tough challenge for both of us," the Serb said. "He's a big guy, big serve. He has weapons, obviously serve and forehand.

"I'm hopefully going to be able to feel my best."

REUTERS