Cullen, who plays his club rugby with Bruff, is the youngest member of the Munster academy and played for the Irish U18 Club side against Italy, Scotland, England and France in 2013.
Rockwell educated hooker McNulty impressed for the Munster U19s this season as they were pipped to the Interprovincial title by a last-minute converted try by Connacht in their final game.
Prop O'Donnell and second-row Bradshaw Ryan also featured heavily in the Interprovincial campaign and both will be keen to see some action off the bench.
Munster U19s will face Australia Schools at Thomond Park on Tuesday, December 17th (ko 5pm).
IRELAND U19 TEAM v Australia Schools - 14th December 2013
1. Jeremy Loughman (Blackrock College - Ulster)
2. Sean McNulty (UCD - Munster)
3. Oisin Heffernan (Lansdowne FC - Leinster)
4. David O'Connor (Blackrock College - Leinster)
5. Alex Thompson (Methodist College - Ulster)
6. Josh Murphy (UCD - Leinster)
7. Rory Moloney (Buccaneers RFC - Connacht) capt
8. Lorcan Dow (Queen's University - Ulster)
9. Jack Cullen (Bruff RFC - Munster)
10. Ross Byrne (UCD - Leinster)
11. Jack Owens (Campbell College - Ulster)
12. Conor McKee (Methodist College - Ulster)
13. Gary Ringrose (UCD - Leinster)
14. Ciaran Gaffney (Galwegians RFC - Connacht)
15. Billy Dardis (UCD - Leinster)
16. Stephen Weir (Methodist College - Ulster)
17. Michael Lagan (Methodist College - Ulster)
18. Mike O'Donnell (Crescent College - Munster)
19. Frank Bradshaw Ryan (Shannon RFC - Munster)
20. James Gallagher (Ballymena RFC - Ulster)
21. Conor Young (Instonians RFC - Ulster)
22. Josh Bingham (Methodist College - Ulster)
23. Piers O'Conor (Eastbourne College - Exile)