Australia playmaker Berrick Barnes has been ruled out for six weeks with a dislocated thumb but will be fit to face the Lions.
Barnes suffered the injury in a tackle during New South Wales Waratahs' Super Rugby home defeat to the Cheetahs on Friday, having just come back into the side after recovering from a knee injury.
Barnes's setback adds to the Sydney outfit's problems, with their hopes of making the play-offs already looking thin after starting the season with three defeats in four matches under new coach Michael Cheika.
But Barnes will have enough time to prove his fitness ahead of this summer's eagerly-awaited clash with the Lions.
That is a major boost for the Wallabies, who had already lost their key forward David Pocock to injury.