On-loan Southampton forward Barnard missed training on Thursday due to a tight hamstring and is set to be closely monitored by caretaker manager Tony Philliskirk and his staff.
Latics' FA Cup goal-hero Matt Smith came off the bench to score his fourth of the competition during Tuesday night's fifth-round replay defeat to Everton and could push for a start up front, although Robbie Simpson would provide a more like-for-like replacement if Barnard fails to recover in time.
Experienced defender Cliff Byrne damaged his ankle earlier this week and is set to spend two weeks on the sidelines.
Cristian Montano is back in training following a two-month lay-off with a thigh problem, but Philliskirk believes the winger needs a reserve outing before being considered for first-team duties.
Youssouf M'Changama (knee) is expected to miss the rest of the season.