Injuries on Saturday to both Oupa Manyisa and Siyabonga Sangweni added to a growing casualty list at the defending champions, who despite the setbacks remain in second place after beating Free State Stars 1-0 at Orlando Stadium on Saturday night.
Manyisa was stretchered off late in the game after suffering a recurring hamstring problem that has bothered him all week while Sangweni did not make the kickoff because of a knee problem.
Sangweni hurt himself in the warm-up and had to be hastily removed from the team sheet. He was hurt on Wednesday when Pirates won away at Sundowns but recovered significantly in the build-up to Saturday's game to be included, only to suffer a further setback.
The extent of the two injuries will only be known today after both have further medical examinations but De Sa said he feared "the whole spine of the team will be out for a while".
Also injured is goalkeeper Moeneeb Josephs, with a shoulder problem. He had been dropped in midweek but was on the bench for the game against Sundowns.
On Saturday, however, inexperienced Brighton Mhlongo took his place among the substitutes.
Josephs had shoulder problems last season that ruled him out at times during Pirates' successful championship-winning season.
Already out are Rooi Mahamutsa and Andile Jali. Benni McCarthy's planned return in midweek was postponed.
"There is no quick fix. These players need time out," De Sa said.