The Sixways boss has also spoke about a change in emphasis this week in preparation with intensity levels again cranked up to ensure the Warriors arrive at Vicarage Road in top condition.
"We will look at one or two changes and some have been enforced," admitted Hill.
"Shaun Perry has a bit of an ankle injury so he will definitely be out. We have one or two issues so perhaps there might be a few changes yet.
"Before Gloucester we looked to keep our power dry and our defence and attack work was a little more passive, we reduced the work load and intensity hoping we would get a good reaction and be fresh for the weekend," he added.
"That backfired so what we have done in previous weeks, before Argentina, Rebels and Sale, we have done again with some full contact and high intensity sessions and that will be carried into the weekend.
"You try things and we felt that was the right thing to do last week, keep the power dry, keep the body fresh and avoid the soft tissue injuries so we could hit Gloucester with everything we had.
"That didn't happen so we have reverted back to Plan A and have smashed each other around this week. We have upped the intensity and contact this week and we should be a lot better."