Ward, not expected back for Saturday's derby clash at Barnsley, has missed the last four matches due to an Achilles injury, Darius Henderson is a long-term absentee and Daniel Bogdanovic is currently suspended, leaving Ched Evans and Richard Cresswell as the only two senior forwards.
Speed said: "I think it might be a little bit too early for Jamie. There's always a chance and you never know but I reckon he might have to wait. He's been getting treatment so we'll see how he responds.
"Obviously we'd rather he was available. But, even though we are well down in terms of numbers in that department, we can't afford to take unnecessary risks. We'll just have to see how it goes."
Mark Yeates is expected to return to contention after a back injury forced him to miss the defeat at Bristol City.
Source: PA
Source: PA