A further six players will be added to the party on June 11 and Deans says Cooper could be in that particular mix after insisting his omission has nothing to do with the 24-year-old's public outburst last year when he described the national set up as a 'toxic environment'.
Instead, the man charged with leading the Australians to a repeat of their 2001 series success against Britain and Ireland's elite says he wants to see Cooper show a stronger side to his defensive game by regularly lining up in the No10 channel rather than defending at full back.
"People will say that's the end for Quade, but that's not the case. There's still six positions to be resolved," said Deans, who insisted that Cooper would have the opportunity to show his worth when the Reds host the Lions at the Suncorp Stadium on June 8.
"[Personality] doesn't come into it; we're here to select what we believe what is the best mix and combination to win this series. I know no one believes it but it is genuinely not about personalities.
"We all know Quade's history in the group. I've selected him on 38 occasions, I understand. So he's had a lot of faith and support from me. To suggest otherwise is nonsense.
"Test rugby is another level from Super rugby and we would like to see Quade defend in the front line. We would like him to assert himself physically in the game because that's an element you can't avoid at Test level.
"It's the whole game. Assertiveness goes both ways in attack and (defence) - that's what we'd like to see particularly in that outing (between the Reds and Lions)."
Rebels utility back O'Connor is the early favourite for the Qantas Wallabies fly-half berth, with Deans admitting that the 22-year-old is the current front runner for the opening Test on June 22.
O'Connor has limited experience in the playmaking role having won the majority of his 37 caps on the wing or at full back but Deans has been impressed with his performances in the pivotal position in this season's Super XV.
"James is a bloke that traumatises defences. He keeps the attack very square, which provides opportunity for the channels around him," added Deans.
"None of our five-eighths have had consistent time at international level in the last couple years, that's been an element of frustration for us, but the great thing is we've got a number who are capable of playing at that level and it's just a matter of identifying the ones that we believe will serve the team's needs best.
"In the first instance, James has got that opportunity."
For the full Qantas Wallabies squad please click here