Tomlin sustained the injury in the game against West Ham.
“Lee thought he heard a crack at the time and the doctor initially felt there might have been a break,” said Posh boss Darren Ferguson.
But Ferguson was happy that the injury was not as bad as first feared.
“Had that been the case it could have meant 10 weeks out, so we are relieved the injury has proved not to be as serious as it initially looked,” Ferguson added.
