Harrison, who missed last Sunday?s 22-12 loss to the Sydney Roosters because of a family emergency, will line up against the Cowboys at five eighth, with Jamie Russo moving back to the halfback role.
Prop Andrew Hart will miss the game with a throat problem, which means Duncan MacGillivray gets his first start of the 2003 NRL season.
Jess Caine is the new face on South Sydney?s bench.
1. Brad Watts 2. Nathan Merritt 3. Lee Hookey 4. Russell Richardson 5. Luke McDougall 6. Ashley Harrison 7. Jamie Russo 8. Duncan MacGillivray 9. Jason Death 10. Luke Stuart 11. Justin Smith 12. Mark Minichiello 13. Shane Rigon Interchange 14. Mark Meredith 15. Jamie Fitzgerald 16. Jess Caine 17. Shane Walker 18. James Storer