Two-times Wimbledon champion Petra Kvitova will not be able to play competitive tennis for around six months, a Czech news website said, citing the surgeon who operated on Kvitova's playing hand after it was injured in a knife-attack. "When we talk about (competitive) pressure on the hand, we are talking about a period of around six months (before that would be possible)," Radek Kebrle was quoted by aktualne.cz website as saying.