The tennis world number 11 said she would need to consult specialists about the injury, and gave no indication when she might be able to play again.
"In my attempt to defend myself, I was badly injured on my left hand," she said on her Twitter account @Petra_Kvitova.
Kvitova was attacked in her flat in the city of Prostejov, about 260 km southeast of Prague, the site of a tennis club where she, men's world number 10 Tomas Berdych and other top-ranked Czech tennis players train.
Karel Tejkal, spokesman for the Czech Fed Cup team, told Czech media the morning attack had been "a random criminal act" and she had not been specifically targeted.
The Czech Republic won the Fed Cup, the premier national team competition in women's tennis, for the third year in a row in November.
Karel Tejkal, spokesman for the Czech Fed Cup team, told Czech media the morning attack had been "a random criminal act" and she had not been specifically targeted.
The Czech Republic won the Fed Cup, the premier national team competition in women's tennis, for the third year in a row in November.
