All but two of the lucky losers are already out.
"He’s practicing 100 percent, hitting the ball super hard, hitting the ball really, really well," Carlos Alcaraz said of Rafael Nadal.
"I am still recovering, but getting better. Health always comes first," Serena said.
The WTA's prestigous season-ending event will be played from November 2-9.
This week's ATP ranking risers - and a special milestone for Daniil Medvedev
After Bernard Tomic lost the shortest-ever Challenger final, nemesis Nick Kyrgios responded.
The Pole celebrates 125 weeks at No.1 but will she finish the year there?
