Lane, son of former Wallabies centre and 1999 World Cup winning assistant coach Tim Lane, will provide back to Berrick Barnes and Bernard Foley. He could come into contention to face the British & Irish Lions if Barnes gets called up to face Warren Gatland's side for the Wallabies.
The 20-year-old Lucas has been a star of the Australian Sevens side and is aiming to follow in the footsteps of elder brother Ben, who plays for the Reds. He will battle with Brendan McKibbin and Grayson Hart for the No 9 jersey.
Hooker Luke Holmes, 28, has played Super Rugby for both the Western Force and Melbourne Rebels. Cheika has also given rising teenage star Jed Holloway a chance to play at the highest level in club rugby in Australia by giving him a contract.
The 2013 British & Irish Lions face the Waratahs on 15 June at the Sydney Football Stadium.