Oesterle was reassigned to AHL Calgary on Friday, according to Randy Sportak of The Hockey News.
Oesterle was placed on waivers by the Flames on Thursday, Pat Steinberg of Sportsnet 960 The Fan reports.
Oesterle has been a healthy scratch for 10 straight games.
Oesterle has played in seven of the Flames' nine games in January.
Oesterle was called up by the Flames on Wednesday.
The Flames placed Oesterle on waivers Thursday, Elliotte Friedman of Sportsnet reports.
Oesterle agreed to a one-year, $925,000 contract with Calgary on Sunday.
Oesterle (undisclosed) was removed from injured reserve Thursday, per CapFriendly.
Oesterle (undisclosed) was placed on injured reserve Monday.
Oesterle heads into the holiday break mired in a 10-game point drought, and the defenseman is minus-8 over that span.