Returning Wallabies star James O’Connor regards Saturday night’s Test against Argentina as a “must-win” encounter despite the Wallabies having already blown their chance to lift the Tri-Nations trophy. It means the Wallabies need to defeat Argentina by 101 points this Saturday at Bankwest Stadium to win the Tri-Nations title. But O’Connor, who has missed Australia’s past three Test with knee and foot injuries, said the Wallabies still had plenty to play for. “We’re taking this game as a must-win game for us,” O’Connor said. “Argentina have been a formidable side ... they know how to play the margins, the play the territory really well.