The Raiders have also named centre Adam Mogg in their starting team, subject to the result of a judiciary charge.
Mogg has been charged with a grade 1 dangerous throw from Sunday�s loss to the Melbourne Storm, which threatens to sideline him for one match. The Raiders have until midday tomorrow to make a decision on whether they contest the charge.
The Raiders are already missing 11 members of their full-time squad.
Schifcofske will need four to six weeks to recover from a rib cartilage injury and Chalk is his first-choice replacement.
Chalk, 24, was recruited from Queensland Cup team the Ipswich Jets in 2003 and made his NRL debut for the Raiders last season. He has played five NRL matches and shot to attention with four tries in just his second game.
Raiders coach Matt Elliott has also retained young players Terry Campese, 20, and Todd Carney, 18. Despite back-to-back losses, Elliott remained positive in his approach to Sunday�s game against the Knights.
�We can�t focus on who we don�t have,� Elliott said. �We have to focus on the qualities that exist in this squad and how to get the best out of these players.�
CANBERRA RAIDERS v NEWCASTLE KNIGHTS Sunday, May 1, 2.30pm At EnergyAustralia Stadium
1. MARSHALL CHALK 2. MATT GAFA 3. PHIL GRAHAM 4. ADAM MOGG 5. DAVID HOWELL 6. TERRY CAMPESE 7. LINCOLN WITHERS 8. BEN CROSS 9. ALAN TONGUE 10. TROY THOMPSON 11. MATT ADAMSON 12. KRIS KAHLER 13. JASON CROKER
14. TODD CARNEY 15. JOSH MILLER 16. IAN HINDMARSH 17. TYRAN SMITH