The pair sustained injuries in the Bombers' seven-point loss to the Swans on the weekend and will be sidelined for the time-being.
Despite playing out the game, scans have confirmed that Langford will miss the next three weeks due to a minor hamstring strain.
The injury is a massive blow for the Bombers, as they look to land a top-eight finish this season.
“We’re disappointed to be without him (Langford) for a period of time", Mahoney said, per The Herald Sun.
"Particularly given he had just returned from a similar strain after completing a thorough rehab program and performed very well yesterday.”
However, despite undergoing surgery for a broken thumb, Essendon skipper Heppell is set to miss only a week of footy.
“Dyson played on (Sunday) with that broken thumb and he went for scans this morning which confirmed a fracture" said Mahoney.
“He has undergone surgery this afternoon and he will likely miss this week but we will wait and see how this progresses over the coming days.”
There is more positive news for Bombers fans however, with defender Jayden Laverde likely to face the Bulldogs on Sunday.
Despite being forced off the ground late into the Swans match, the defender has been cleared of any serious shoulder damage and will face a fitness test this week to determine his availability.
With the Bombers still in contention to make the eight, this weekend's clash remains as a must-win match.