The world number 11 had cuts on her left hand, in which she holds the racket, after fighting the burglar.
"Petra Kvitova was attacked in her flat this morning, it was a random crime, nobody was going to attack or rob her as Petra Kvitova," spokesman Karel Tejkal told AFP.
"She was injured with a knife during the attempted burglary. Her life is not in danger," Tejkal added.
The Dnes daily said the 26-year-old world number 11 had cuts on her left hand, in which she holds the racket, after fighting the burglar.
"What happened to me was not pleasant at all but it's over now," Kvitova said on Facebook.
"I trust the doctors and I believe it will all end well. Don't worry about me," she added.
Radka Milosevska, spokeswoman for the Prostejov hospital, told AFP Kvitova had been treated with knife cuts and released.
Local police spokesman Frantisek Korinek said the attack had occurred before 0730 GMT on Tuesday near the town centre and that the burglar was still at large.
The police have the burglar's description, he told AFP but declined to confirm media reports that Kvitova had let the burglar in as he pretended to be a technician checking boilers.
The burglary adds a sombre ending to a rather lacklustre year for Kvitova, who slid from sixth in the world in January to 16th in August.
She sacked two coaches before winning the Wuhan Open in China in October after a 13-month title drought.
She added a victory at Zhuhai, China in November and was on the Czech Republic team that won the Fed Cup later that month, beating France for its fifth title in six years.
On December 1, Kvitova hired a new coach, Czech Jiri Vanek, who had led her Fed Cup teammate Karolina Pliskova to this year's US Open final.
Bronze medallist from the Rio Olympics and Wimbledon champion in 2011 and 2014, Kvitova is also recovering from a stress fracture to her foot which has ruled her out of the Hopman Cup starting on January 1.
"The results of a scan have confirmed that my foot is healing but not as quickly as we would have liked," she said earlier on Tuesday.
Kvitova was hoping to start next year at Sydney on January 8 to warm up for the Australian Open the following week.