Pocock said he wouldn't find out how long he was likely to be sidelined until after undergoing keyhole surgery on Tuesday.
"He (the surgeon) said he wanted to avoid putting a timeline on it till after he actually got in there to have a look," Pocock said.
Pocock's injury continued the run of outs in the Wallabies leadership group, with Genia the only one currently fit.
Lock and first-choice captain Horwill (hamstring), Pocock, and backs James O'Connor (hamstring) and Pat McCabe (foot) are all currently injured.
Neither Deans or Genia was worried about any shortage of leadership, both nominating lock and former Force captain Nathan Sharpe as an obvious senior figure.
In Pocock's absence, either Michael Hooper or Liam Gill will start on Saturday, with Deans suggesting the former's greater background with the team might be enough to earn the Brumby-turned-Waratah the starting spot.
Hooper earned his first three caps off the bench in the June Tests against Scotland and Wales, while the uncapped Gill was overseas captaining the Australian under 20 team.
"They are both good players. Obviously Michael has got more background with us," Deans said.
"Liam hasn't had a start yet, so that probably gives Michael the advantage."
Pocock described Hooper and Gill as very capable players and said he would speak to both of them in the lead-up to Saturday's game.
"We'll go through some footage and I'll be giving them as much, or as little, advice as they want leading in to the game.
"It's such a huge opportunity for one of those two young blokes, I'm sure they will be itching to get out there."
Deans offered few clues to his starting lineup at training on Monday.
Fullback Kurtley Beale, who was widely criticised for his performance last Saturday, raised plenty of cheers with a couple of intercepts.
Pocock said he had spoken to Beale, but stressed the Rebels back was far from the only Wallaby that needed to lift in form after last Saturday.
"He's obviously disappointed with his performance and wants to make up for that, and learn from it, so I think it's important that we support him," Pocock said.
"There's a lot of guys in the team that will be looking long and hard at their games over the next few days."
- AAP
