Well, the club confirmed it today, tweeting:
Tests have confirmed Petr Cech has a groin muscle injury. Further tests are awaited to determine the length of his recovery period. #CFC— Chelsea FC (@chelseafc) December 31, 2012
So Turnbull becomes an option for fantasy managers who aren't on Hugo Lloris cheap, who are on Brad Guzan for cheap and are looking for an exit strategy, or any managers playing keeper roulette.
More injury and suspension news to come.