Andy Murray has announced his split with coach Ivan Lendl, with the pair mutually agreeing to end their relationship.
Murray's recent stint with Lendl was their second together, the first having seen Murray win the US Open, Wimbledon and the first of his two Olympic gold medals.
Lendl resumed his role as Murray's coach in June last year following the Briton's split with Amelie Mauresmo.
He promplty won Wimbledon and a second Olympic gold, but his 2017 season was severely hampered by injuries.
Murray lost in the fourth round of the Australian Open to Mischa Zverev but did reach the semi-finals of the French Open, only to be beaten by Stan Wawrinka in five sets.
The 30-year-old was significantly affected by a hip injury at Wimbledon and a quarter-final defeat to Sam Querrey proved his last match of the year, with Murray losing his number-one ranking and missing the US Open as a result of his lay-off.
Murray, who will continue his efforts to get back to fitness in Miami before heading to Australia to prepare for the opening grand slam of 2018, said: "I'm thankful to Ivan for all his help and guidance over the years, we've had great success and learned a lot as a team.
"My focus now is on getting ready for Australia with the team I have in place and getting back to competing."
Lendl added: "I wish Andy well going forward. We had a great run and a lot of fun."
Murray has dropped to 16th in the world rankings in his time off the court, but will hope his time away will prove to be a blessing.
Roger Federer and Rafael Nadal both benefited from extended absences and greater management of their schedules in 2017. Federer won the Australian Open and Wimbledon while Nadal triumphed at the French Open and the US Open.
Novak Djokovic, having struggled with an elbow injury in 2017, has also not played since Wimbledon, dropping to 12th in the rankings, though he has decided Andre Agassi will remain his coach in 2018.
Murray and Djokovic's respective slide down the rankings sets up some potentially fascinating first-week matches at the Australian Open, which starts in Melbourne on January 15.
|A Mourinho myth? Man United booked for simulation more than any Premier League side|
|Eagles QB Wentz out for season with torn ACL|
|Brook to face Rabchenko in light-middleweight bow|
|Yankees confirm Stanton deal|
|Clermont irked by ´absurd´ Saracens saga|
|Bairstow wants England to regain trust|
|Ronaldo´s ego is his biggest motivator - Valdano|
|Bayern threaten legal action over Leno transfer rumours|
|Thompson welcomes golf´s change in policy over viewer call-ins|
|Potter delighted by underdog Ostersunds´ trip to Arsenal|
|Chelsea can bounce back from West Ham loss, says Conte|
|Real Madrid will relish PSG test, says Xabi Alonso|
|Conte urges Chelsea to be ´positive´ over Barca Champions League draw|
|Heynckes wary of Besiktas threat|
|Ostersunds handed fairytale Arsenal tie, Napoli face Leipzig|
|Taylor pays moving tribute to Crowe after equalling century record|
|Emery: PSG ´can compete with Real Madrid´|
|Totti urges Roma focus on Serie A despite encouraging Champions League draw|
|Europa League: Last 32 draw in full|
|Messi faces toughest foe in Champions League|
|Tigers confirm broken jaw for Veainu as Tuilagi nears return|
|AC Milan signed too many players, admits Fassone|
|Real Madrid face PSG, Chelsea drawn with Barcelona|
|FA seeking information over Manchester derby incident|
|India agree to be Afghanistan´s first Test opponents|
|He is one of the best strikers in the Premier League - Wilshere hails Giroud|
|Jamshed banned for failing to co-operate with PCB anti-corruption unit|
|Mata: No time to mourn derby defeat|
|Hitzfeld tells Nagelsmann to honour Hoffenheim contract|
|Amor: Mascherano future to become clear soon|
|Good things come to those who wait - Shubhankar wins Joburg Open in Monday finish|
|Huddersfield confident of Chelsea scalp - Ince|
|Sea Eagles facing sanctions over salary cap breach|
|Paine denies Aussies have crossed line with Ashes sledging|
|Road to Super Bowl hits speed bump as Eagles sweat on Wentz fitness|
|Taylor hits record ton as Windies chase mammoth total|
|Oladipo´s career performance keeps Pacers rolling|
|De Bruyne: Man City have to enjoy derby victory|
|Suspended Smith-Schuster watches on in Steelers helmet|
|Bancroft and Warner ´kissed and made up´ after Adelaide mix up|
|There is no-one like Messi – Alcacer|
|Pederson unwilling to comment on Wentz amid ACL fears|
|Kane: Bring on the best in Champions League|
|Neville: Lukaku needs to believe amid Man United struggles|
|Fitzgerald now third all time in receiving yards|
|Eagles QB Wentz suffers knee injury|
|Messi best player of all time – Rakitic|
|Gattuso: I´m even tense playing football with my son|
|Suarez admits Villarreal red swung it for Barcelona|
|Villarreal win ´crucial´ for Barcelona boss Valverde|
|O´Hair and Stricker claim QBE Shootout crown|
|Sublime O´Sullivan equals major record with sixth UK Championship win|
|Villarreal 0 Barcelona 2: Suarez, Messi restore five-point LaLiga lead|
|AC Milan 2 Bologna 1: Bonaventura brace breaks Gattuso´s duck|
|Leinster end Exeter home streak, La Rochelle shine again|
|Texans QB Savage suffers concussion; brief return sparks controversy|
|Guardiola: Man City are an honest team|
|Snow joke! Bills and Colts play in brutal blizzard|
|Mourinho: Herrera denied clear penalty in derby defeat|
|Mourinho admits title race ´probably´ over|
|Josh Gordon scores first touchdown in four years|
|Simeone defends Atleti´s style after battling win over Betis|
|Manchester City´s 14th win on the spin sets new top-flight record|
|Manchester United 1 Manchester City 2: Otamendi strikes massive blow in Premier League title race|
|Bath concerned by injury to Wales forward Faletau|
|Allardyce praises ´brave´ Pawson after penalty decision|
|Atletico Madrid set club-record unbeaten run in LaLiga|
|Ajax 3 PSV 0: Eredivisie title race gets new lease of life|
|Klopp involved in post-match spat with reporter|
|Rooney backs awarding of ´clear penalty´|