Full-back Meredith (hip) and striker Hines (ankle) are serious doubts and may both require scans to determine the full extent of their injuries, while defender Darby is struggling with a groin problem and could undergo a late fitness test.
Manager Phil Parkinson will be able to call on loanees Craig Forsyth and John Egan, though, as his fourth-placed side look to close in on the automatic promotion places.
Watford winger Forsyth and Sunderland defender John Egan were not eligible for the midweek penalty shootout win over Northampton in the FA Cup.
Winger Kyel Reid (groin) and central defenders Luke Oliver (Achilles) and Andrew Davies (knee) remain long-term absentees.
Exeter striker Guillem Bauza came through a reserve game in midweek unscathed to give Paul Tisdale another attacking option ahead of the clash.
The Spanish striker netted in a 1-1 draw with Bournemouth's second string, having missed the club's last five games, but midfielder Arron Davies had to watch from the sidelines as he continues his recovery from his calf injury.
The Grecians face Phil Parkinson's side, who pulled off another cup victory on Tuesday night, on Saturday before a Tuesday night trip to npower League Two leaders Gillingham, back to back away trips that will be real test for Tisdale's troops.
``We have two very tough games now in Bradford and Gillingham,'' the City boss said. ``Our players will need a bit of a break ahead of what will be a tough four or five days.
``There is a lot of travelling involved but we aren't unused to that. It is something we are used to and have to do. I'd like to get four points from those two games and if we do I'll be delighted.''