Bolton will be without both Mark Davies and Matt Mills when Charlton visit the Reebok Stadium.
The pair picked up injuries in the Trotters' 2-2 draw to Huddersfield last Saturday and are now set for extended spells on the sidelines.
The club confirmed via their Twitter account that Davies, who landed awkwardly during the clash with the Terriers, will miss three months after having surgery on a shoulder injury.
Mills, meanwhile, came off five minutes before the end in that contest with a thigh injury which will now keep him out for six weeks.
It is a bitter blow to manager Dougie Freedman who is already without long-term absentees David Wheater and Josh Vela (both knee).
Midfielder Stuart Holden is back in training from his knee injury although he is still a couple of months away from a return to first-team action.
Dan Seaborne should return to the Charlton squad for the trip.
The defender, who has extended his loan spell from Southampton on a week-by-week basis, missed last weekend's 2-2 draw against Brighton through illness.
Seaborne will be expected to go straight back into the side with Charlton having not conceded a goal in the four games he has played since moving to The Valley.
Frontman Ricardo Fuller is close to returning from a hamstring injury but full-backs Cedric Evina (knee) and Rhoys Wiggins (metatarsal) are still out.
Striker Leon Clarke is back with the Addicks after completing his loan spell at Scunthorpe and goalkeeper John Sullivan has also returned to south-east London following his stint with Colchester, but midfielder Eggert Jonsson has gone back to Wolves.