Djokovic: I feel your pain, Andy

impacting on his start to this year. But he has taken a world view to put his struggles into perspective.

“To sit here and talk about how tough it is, and you have people starving to death, for me there is no point in talking about it,” he said.

“As an athlete I have to face these challenges. If I overcome them or not, it’s just a matter of the work I have put in, luck and circumstances. I don’t like to talk any more about what is tough, what is not tough. I’m not worried about the elbow.

“At the moment I’m not playing at the level I wish to, but I understand that it is a process that obviously takes time. I’m trying to not give up, and create the best out of this situation.

“The best practice that you can have is a match, and I haven’t had too many matches. I never thought I was going to be challenged in this way mentally.

“At times I do lose confidence on the court. But the more matches I play, the better it is. The more I win, of course, the better it is.”

It was at times a struggle for the 31-year-old Djokovic against a Spaniard 10 years his junior. A tight first set was won on a tiebreak, after which Djokovic ground down Munar to take his second match without dropping a set. The Serb will now face another Spaniard in 13th seed Roberto Bautista Agut.

Alexander Zverev also made a nervy start in Paris before reaching the third round with a 2-6, 7-5, 4-6, 6-1, 6-2 win over Dusan Lajovic.

The German second seed smashed a racket in frustration after being broken in the third game of the second set, having dropped serve twice in the opener.

But the 21-year-old’s superior class eventually told, setting up a meeting with Bosnian Damir Dzumhur.

Fourth seed Grigor Dimitrov, who struggles on clay, was caught up in a four-hour dogfight with Jared Donaldson, eventually seeing off the 57th-ranked US youngster 6-7, 6-4, 4-6, 6-4, 10-8 to collect the 50th win of his career in a Grand Slam match.