Fellow midfielder Josh Simpson has recovered from his illness, however, and could replace Frecklington at Vicarage Road.
Winger Chris Whelpdale remains sidelined with a groin injury so Dominic Green could continue after being drafted into the side since returning from a loan at Chesterfield.
Defender Ryan Bennett will be out for several more weeks yet as he recovers from an ankle injury as Posh look for a first away win of the season which would drag Watford closer to the relegation zone.
Source: Team Talk
Source: Team Talk