The 23-year-old marked the start of the Rugby Championship campaign with a shocker against the All Blacks in Sydney and was subsequently benched for the return fixture in Auckland.
Injury to Drew Mitchell saw Adam Ashley-Cooper moved to the wing and Beale recalled at full back for the win over the Boks but the Rebels star again failed to shine despite a 26-19 success in Perth.
Now Beale has been replaced by Berrick Barnes in the No15 shirt for the game against the Pumas, even though Barnes hasn't played any international rugby at full back.
It signals a stark change in fortunes for Beale, who won the John Eales Medal as Australia's Player of the Year last season.
Widely regarded as the best full back in the world game in 2010 and 2011, Beale faces a real fight to feature for the full 80 when the Lions come calling next summer.
And while Deans hasn't written off one of his big names, he admits Beale has plenty of work to do prior to the Lions' arrival Down Under.
''One of Kurtley's greatest points of difference was his footwork and his explosiveness. He had the ability to create a foot race and win,'' said Deans.
''The defensive lines in Test rugby have stiffened up. Every side is finding it harder to score, and that side of the game is getting more difficult. And that's the side of the game which Kurtley is most remembered for.
''It is also fair to say, whether it be as a result of injuries or whatever, he is not as sharp as he has been. He's working hard on that, and will get back there.
''He has great instinct, and reads body language superbly. But to maximise that you have to be really at the top of your game and on top of your fitness.
''And he's not at the moment. That's evident. He's not in his 2010 shape.
''Still you don't suddenly go from hero to zero. He's somewhere in between, and continues to offer us an awful lot.
''He will provide a lot coming off the bench late when he is fresh and up against tiring bodies.''