Martina Navratilova led the well-wishers after two-time Wimbledon champion Petra Kvitova injured her left hand in fending off a knife attack in her own home on Tuesday.
Kvitova says she is "fortunate to be alive" after sustaining an injury to her racket-holding hand during the assault and robbery in Prostejove, Czech Republic.
And Navratilova passed on her best wishes to Kvitova after learning of the "awful stabbing".
Just finding out about @Petra_Kvitova and the awful stabbing and injury to her hand- pulling for you Petra, všichni držíme palce!!! Xoxo— Martina Navratilova (@Martina) December 20, 2016
Navratilova wrote on Twitter: "Just finding out about @Petra_Kvitova and the awful stabbing and injury to her hand- pulling for you Petra, vsichni drzime palce (all fingers crossed)."
The 60-year-old 18-time grand slam singles champion was born in Prague, capital of the Czech Republic.
Kvitova is seeing a specialist to determine the extent of the injury.
She is already undergoing treatment for a stress fracture to her foot which could rule her out of the Australian Open, which begins in Melbourne on January 16.
The tournament organisers wrote on Twitter: "The AusOpen family wish @Petra_Kvitova all the very best for a complete recovery."
Wimbledon, where Kvitova enjoyed her greatest successes in winning the singles title in 2011 and 2014, added: "The thoughts of everyone at Wimbledon are with Petra Kvitova, and we send her our best wishes for her recovery."
Many current and former players added their thoughts.
Victoria Azarenka wrote: "My prayers and best wishes to @Petra_Kvitova stay strong."
Caroline Wozniacki added: "Just heard what happened to @Petra_Kvitova ! All my thoughts are with her today! So scary! One of the nicest people I know!"
Marion Bartoli wrote: "@Petra_Kvitova All my prayers & thoughts are with u Petra.This is just beyond awful!! U are so strong , u will come back to us on the @WTA."
My thoughts are with @Petra_Kvitova . Terrible news.— Aga Radwanska (@ARadwanska) December 20, 2016
World number three Agnieszka Radwanska tweeted: "My thoughts are with @Petra_Kvitova. Terrible news."
Caroline Garcia, who won the French Open doubles title alongside Kristina Mladenovic earlier this year, added: "Can't believe what happened to @Petra_Kvitova today. All my thoughts and support to one of nicest girl on the tour..."
Mladenovic wrote: "@Petra_Kvitova It's horrible and terrifying reading you Petra... I'm sending you all my love and support to overcome this difficult period."
Men's world number 28 Feliciano Lopez posted: "All my thoughts with you @Petra_Kvitova I am sure you'll get over this"
Italy's Sara Errani wrote: "I can't believe what happen to @Petra_Kvitova .. i hope you get well really soon! Stay strong"
American CoCo Vandeweghe added: "All my thoughts and prayers are with @Petra_Kvitova Speedy recovery!"
World number seven Garbine Muguruza posted: "Just learned what happen to @Petra_Kvitova! Stay strong & recover well!"
Olympic gold medallist Monica Puig of Puerto Rico wrote: "Thinking of you @Petra_Kvitova .. stay strong! We are all with you"
Former world number one Ana Ivanovic added: "My thoughts and prayers are with Petra! She's a great fighter and I am positive she will be ok! @Petra_Kvitova thinking of you!"