Hill has admitted he is likely to switch Chris Jones to the back row, but has also been given some positive news with Percival back and eager to feature after missing the recent victory over Bath Rugby.
"We have got a good back row available and will look to put Chris Jones back in," revealed Hill.
"Adam Balding is going to be out for around three months with a very acute hamstring injury and Kai Horstmann is out for about two months also which is a blow.
"Richard Muagututia has flown back to Canberra in Australia, which we always knew he would have to do after three months as a regulation. He will be away for a week to 10 days so that leaves us three players light.
"With Neil Best having broken a forearm, he will be in plaster for six weeks, we are suddenly down.
"However, Matt Kvesic is playing very well for us, Sam Betty has really stepped up from Cornish Pirates this year and Chris Jones can come in as a lineout option.
"With James Percival back fighting fit he will move into the second row. At the moment we can still put a very good back row out."
Hill also admitted he was hoping for positive news over the fitness of England front row Matt Mullan after he was forced off against Bath.
"With Matt we are waiting on scans, but that looks like it could be four weeks," he added.
"We are without three looseheads with Ceri Jones for a few more months still and George Porter having burst an appendix so we need to keep him back for a week to 10 days.
"Bruce Douglas will switch across and some good news is that Oliver Tomaszczyk is pushing for a recall."