The Wallabies regular left the field for a HIA in the second half, coach Dave Wessels fearing a trip to hospital would reveal a serious neck injury as the side dropped back to fourth ahead of a bye.
But Toomua was cleared and travelled with the side back to Sydney, the inside centre unlikely to miss a game given the Rebels have a next-round bye.
Though not yet confirmed, Wallabies Tests against New Zealand are pencilled in for October this year.