As of now no one. Rashad Jennings, Greg Jones, and Chauncey Washington are the guys in the mix right now. We'll probably get definitive word near the end of the preseason, but I'd guess that Greg Jones will wind up with the backup job. Still, I agree that the Jags would use a committee if MJD went down, probably with some combination of the three unless one separates himself from the pack with his productiveness.
Kudos to Leber
for the amazing sig and to Metroid
for the userbar and making them both fit
2008 and 2009 Defunct Dynasty League Champion