If it's your last RB and you are looking for whoever has the most upside, I could see giving Jackson the chance. Apparently, he's going to be the starter. The situation in Arizona is messed up.
12 Team League. We start 2 QBs and get .5 PPR, otherwise standard scoring
QBs: Stafford, Fitzpatrick, Collins
RBs: Charles, Mendenhall, Best, Starks, Carter, Karim
WRs: D. Jackson, Marshall, S. Smith, Green,
TE: Hernandez, Cook