Novak Djokovic has added Goran Ivanisevic to his coaching staff as he bids to retain his Wimbledon title.
Ivanisevic, who became the only man to win the men's singles as a wild card in 2001, will work with Djokovic for the first week of Wimbledon.
However, the 47-year-old - who has also coached Marin Cilic and Milos Raonic - is already hoping to extend his stay in Djokovic's camp, telling Serbian news outlet sportklub: "A bit of a sudden call came a few days ago. I was a little surprised.
"I travelled to Sweden. Nole wanted me to come earlier, but I had a senior tour event agreed. I came here this morning for the first training.
"Unfortunately, it seems that I will be able to be there only in the first week because I have obligations again. I'm trying to postpone them, although there are so many things.
"However, when Novak Djokovic is calling you - you put a lot of things on the side."
Djokovic has admitted grass is the surface he struggles on the most - despite winning Wimbledon four times - which may explain why he has sought the advice of Ivanisevic, who was always most comfortable on grass courts.
Djokovic said: "To be honest, I did struggle a little bit at the beginning, in the first couple of years of my career on the grass to really understand how I need to move on the court, how I need to adjust my swing and my game in general, tactically what I need to do.
"But over the years I guess you learn how to get used to it. Just have some form of a subconscious program from before that you try to unlock and remember and use it for the season every year."