Dev Keeper Help: Deebo or Mattison?

Yo Clan,

Need help in my 12 team full point PPR league. I get a Keeper and Developmental Keeper. For my Keeper I am keeping Josh Jacobs over Aaron Jones. But for my Developmental Keeper should I keep Deebo Samuel who broke his foot in June or Alexander Mattison where I need Dalvin Cook to get injured to see value.

Thanks for any insight you guys have.