As it stands, our defensive options (that is, those are who currently fit and assuming Colo is actually injured) are:
Saylor, Williamson, Perch, Tavernier, Santon, Ferguson, Good, (Anita) [i've put him there because he is a good contingency plan for RB], (Jonas)
Our defence will most likely be:
Anita Saylor Williamson/Perch* Santon
*Depending on the opposition
With that in mind, our backup options would be one of Perch/Williamson, Tavernier and Good which I suppose isn't too bad. An injury to Perch/Williamson/Saylor though and we would definitely be in the s***.