Lawes was treated on the field for 10 minutes at Pennyhill Park before being stretchered off with his neck in a brace.
The 22-year-old was then taken to hospital by ambulance and has since had a scan to assess the extent of the damage. Fortunately for Lawes and for England, the prognosis is nowhere near as bad as at first feared, with the x-ray showing no significant damage.
Lawes is therefore expected to be available for selection for England's first World Cup warm up match against Wales at Twickenham on August 6.
Since making his debut against the Wallabies in November 2009, Lawes has become an integral part of the England set up, with his athleticism and ball-carrying abilities making him one of the favourites for a Lions berth on the hard grounds of Australia in two summers' time.
His potential absence would have been a massive blow to England team manager Martin Johnson, although Lawes did miss the entire RBS 6 Nations campaign after injury ruled him out of the opening fixtures and the form of others in England's winning run ensured he wasn't required for the remainder of the tournament.
While injury to his star second row clearly wasn't part of the plan for Johnson this week, the former Lions skipper was delighted with the rest of the outcome of the behind-closed-doors trial. Only Leicester No8 Thomas Waldrom and Gloucester centre Mike Tindall missed the session, with Waldrom suffering from a calf injury and Tindall excused due to his wedding to Zara Phillips this Saturday.
"It was a good end to the week and the boys enjoyed having a run-out in a different environment," said Johnson.
"Inevitably it was competitive and you wouldn't have it any other way. The whole training camp has had that edge that you want from a group of players vying for 30 spots."
The trial was split into two halves of 20 minutes, with young centre Manu Tuilagi doing his chances of World Cup inclusion no harm by scoring in his team's 11 tries to 10 win.
David Strettle joined Lawes on the casualty list, however, with the Saracens wing carried off with an apparent leg injury during the first period.