For the record, I offered Arian Foster and Zach Miller for Reed.
Expect Miller to blow up now that smokin' Jay is toast.
I get the injury concerns, but I did send the offer before Foster received the Doubtful designation and the reports stated he could play this week (and he still might).
Stating it's my '4th RB' is completely irrelevant. Foster is still a 30 year old injured starting RB in the NFL who gets the majority of the work, and even with injury uncertainty, would greatly benefit your team moving forward. You're lucky you have McKinnon as insurance, but even his workload is TBD with Asiata and Hillman in the mix. Otherwise you're SOL at RB.