This is my best guess on "the right 53" based on who we have right now.
Offense
LT David Mims
RT Ryan O’Callaghan
LG Jon Asamoah
RG Ryan Lilja
TE Tony Moeaki
TE Leonard Pope
TE Jake O’Connell
WR Dwayne Bowe
WR Jon Baldwin
WR/RB Dexter McCluster
WR Jerheme Urban
RB Thomas Jones
FB LaRon McClain
FB Mike Cox
QB Matt Cassel
QB Tyler Palko
QB Ricky Stanzi
Defense
DE Dion Gales
NT Kelly Gregg
NT Jerrell Powe
NT Anthony Toribio
DE Glenn Dorsey
DL Allen Bailey
LB Tamba Hali
LB Derrick Johnson
CB Brandon Carr
CB/S Donald Washington
CB Jalil Brown
Special Teams
K Ryan Succop