Apparently a third partnership for Tati this year. An expert from a tennis.com article:
Even though tennis in the U.S. is most often played on hard courts, there are many clay aficionados in this country, and plenty of clay courts, especially in the Southern states and at private clubs. “Hard courts take a toll on your joints, but clay takes a toll on your muscles,” says Mark Wellington, M.A., C.SC.S., a tennis-performance specialist at the International Performance Institute in Bradenton, Fla. “We usually see a higher incidence of muscle strains and pulls on clay,” he adds, “and players often complain about having ‘heavy’ legs when they start on clay.” According to Wellington, improving your strength, flexibility, and anaerobic conditioning (your ability to move explosively) will help you play better clay-court tennis even before you hit a ball.
It seems he is a fitness trainer more than a coach?
Tatiana Golovin, Timea Bacsinzky, Petra Kvitova, Kristina Mladenovic, Laura Robson