Andy Murray started working with former coach Daniel Vallverdu this month on a short-term basis as the multiple Grand Slam winner works towards rediscovering the form that took him to the top of the world rankings.
Friction has dogged the ATP Player Council, whose president is world number one Novak Djokovic, this year since ATP president Chris Kermode failed to gain support for another term.
More than 70 players and their entourage are confined to their hotel rooms for 14 days and unable to train for the Feb. 8-21 Australian Open after passengers on three charter flights returned positive tests.
Venezuelan Vallverdu currently coaches three-time Grand Slam winner Stan Wawrinka who crushed former world number one Murray 6-1, 6-3, 6-2 in the opening round of this year's French Open.
Sania Mirza and Anna Tchakvetadze of Russia went down 1-6, 6-2, 3-6 to Ana Ivanovic of Yugoslavia and Alla Kudryavtseva of Russia.
'... at times when I see the aftermath of things, I do tend to ask myself if I should just sit back and enjoy my benefits instead of paying attention to other people's struggles.'
Organisers of this year's US and French Opens established bio-secure 'bubbles' for players, who were not allowed to leave their hotel rooms except to train and play.
Wawrinka's last ATP title came in 2017 before the former world number three underwent knee surgery.
Italy sealed a place in the semi-finals of the ATP Cup by winning both singles matches against France
The ATP Tour got on board and last month fans were able to bid for private sessions with celebrated tennis coaches on-site during tournaments in 2021.
Reaching the semi-finals at the 2014 Wimbledon and the 2017 Australian Open remain his best returns in Grand Slams.
Rafael Nadal's path to his Australian Open semi-final against Grigor Dimitrov on Friday has taught the 30-year-old Spaniard one thing -- he's still got it.
'Remarkable discipline for training, competition, sacrifice, perfection, a little crazy but a legend of a bloke. Bravo Andy'.
Grigor Dimitrov reached his first grand slam quarter-final in over two years on Monday by defeating an injury-hampered Denis Istomin 2-6, 7-6(2), 6-2, 6-1 to end the Uzbek wildcard's fairytale run at the Australian Open.