The 22-year-old utility back appears to be battling it out with Christian Leali'ifano and Berrick Barnes for the fly-half jersey for the series opener in Brisbane on June 22 after both Quade Cooper and Kurtley Beale were overlooked by head coach Robbie Deans.
But ex-Wallaby skipper Stirling Mortlock and World Cup winning centre Tim Horan believe O'Connor isn't ready to do the business at outside-half and should instead be employed elsewhere.
"James O'Connor should be on the wing or at inside centre. I just don't think he has the distribution to ignite the backline outside him," was Horan's blunt assessment.
"I'd be picking him on the wing," Mortlock, who works with O'Connor as part of the Rebels' coaching staff, told Triple-M Radio.
"His calling and game awareness at 10, he still needs to work on that.
"He's getting better but he hasn't played that position consistently from the day dot."
O'Connor was switched to fly-half for the Rebels' 30-27 defeat to the Southern Kings last week after previous cameos in the role but has since faced widespread criticism for his game management after the Melbourne-based franchise let a 10-point lead slip from their grasp late on.
There is little doubt that O'Connor will play a key role for the Wallabies against the Lions but where he will be selected remains an area for concern.
O'Connor has picked up most of his Super Rugby game time this season at full back, while the majority of his international career has been spent on the wing.
And while the man himself has repeatedly spoken of his desire to be closer to the action, Mortlock believes that wish will eventually be granted at No12 rather than 10.
"I just think his skill set, currently, is more suited to (inside centre) long term," added Mortlock.
"It looks like James has all the attributes to be a fantastic No12, where he has a little more time and more space for his running game.
"He really is electric when he touches the ball from second-wave attack and that's where as blind winger you get the ball."