The Blues also provided an update on fellow ailing midfielder Matthew Kennedy, who is rehabilitating a knee injury.
Cerra was substituted out of the Blues' rousing victory over Collingwood at the MCG on Friday night during the third quarter after experiencing discomfort.
On Monday evening, via their official injury update, the Blues revealed Cerra has suffered a low-grade strain, meaning he will be sidelined for the next 2-3 weeks. That timeline rules Cerra out of at least this weekend's game against St Kilda and next week's blockbuster against the Demons, with a potential to return for Carlton's trip to the Gold Coast in Round 23.
Meanwhile, Kennedy (knee) will aim to return to running this week, as the Blues hope the ex-Giant can be available late in the season.
The Blues' clash with the Saints this weekend is scheduled for Sunday, August 6 at 3:20 PM (AEST).