As he bids to win a record-setting 25th Grand Slam title, Novak Djokovic is bringing in another member of the “Big Four” as his coach.

Andy Murray, who retired from competition on Aug. 1, 2024, will coach Djokovic through the Australian Open, both men announced Saturday on social media. Djokovic and Murray were part of the so-called “Big Four,” along with Roger Federer and Rafael Nadal. Of that group, only Djokovic remains active following Nadal’s retirement at this week’s Davis Cup finals in Spain.

“We played each other since we were boys — 25 years of being rivals, of pushing each other beyond our limits. We had some of the most epic battles in our sport. They called us game-changers, risk-takers, history-makers,” Djokovic posted on social media over photos and videos from some of their matches. “I thought our story may be over. Turns out, it has one final chapter. It’s time for one of my toughest opponents to step into my corner. Welcome on board, Coach — Andy Murray.”

Djokovic is a 24-time Grand Slam champion who has spent more weeks at No. 1 than any other player in tennis history and is widely regarded as the GOAT of men’s tennis. Murray won three major trophies and two Olympic singles gold medals and finished 2016 atop the ATP rankings.

Both men are 37 and were born a week apart in May 1987. They started facing each other as juniors and wound up meeting 36 times as professionals, with Djokovic holding a 25-11 advantage.

“I’m going to be joining Novak’s team in the offseason, helping him to prepare for the Australian Open,” Murray said in a statement released by his management team, via the AP. “I’m really excited for it and looking forward to spending time on the same side of the net as Novak for a change, helping him to achieve his goals.”

Djokovic split from former coach Goran Ivanisevic in March, and played the rest of the season without a full-time coach. He failed to win a major in 2024, but did win his first Olympic gold medal in singles at the Paris Olympics.

Djokovic leads Murray 11-8 all-time, and 8-2 in Grand Slams.

Djokovic beat Murray four times in the Australian Open final alone — in 2011, 2013, 2015 and 2016.

Two of the most important victories of Murray’s career came with Djokovic on the other side of the net. One was in the 2012 U.S. Open final, when Murray claimed his first Grand Slam title. The other was in the 2013 Wimbledon final, when Murray became the first British man in 77 years to win the singles championship at the All England Club.

Next year’s Australian Open starts on Jan. 12.

(The AP contributed reporting)