Former world number one Novak Djokovic has split from his coach Marian Vajda for a second time.
Serbia's Djokovic, 34, lost the number one ranking to Russian Daniil Medvedev on Monday.
The Serb, a 20-time Grand Slam winner, began working with Slovakian Vajda as a teenager in 2006 and the pair briefly split for one year in 2017.
"Marian has been by my side during the most important and memorable moments in my career," said Djokovic.
"Together we have achieved some incredible things and I am very grateful for his friendship and dedication over the last 15 years."
Djokovic and Vajda agreed to part company at the end of a 2021 season in which the Serb won three Grand Slams.
Having been deported from Australia on the eve of the Australian Open last month, Djokovic returned to action in Dubai last week where he lost to Jiri Vesely in the quarter-finals.
Vajda said he would look back on their time together "with immense pride" and added he was looking "forward to new challenges".