While Ryan Brunt looks likely to return after missing the last two games, Scottish striker David Clarkson will not play again this season as he needs an operation on an ankle problem.
"David needs an operation and won't play again this season," Ward told the Bristol Evening Post. "His ankle is not right so we really have to look at that.
"It is a shame because David is a senior member of the squad and an important player for us, but he just can't get that ankle right."
Clarkson's place in the squad looks likely to be taken by former Sunderland striker Oumare Tounkara who signed a short-term deal with the club on Thursday.
The Pirates announced earlier this week that Seanan Clucas is out for the season with a knee injury, while winger Fabian Broghammer is also a doubt due to an on-going hamstring problem.
But defender Clayton McDonald returns after missing Tuesday night's defeat at Northampton to be present at the birth of his child.