Upside: E.Sanders, Kirk or Desean Jackson?

In half-PPR, I need upside (weak line-up going against first place team).
In the flex, would you rather start Emmanuel Sanders, Christian Kirk or Desean Jackson?

I’d rank upside being desean Jackson but he’s probably least likely to hit his potential ceiling.

Kirk I think would be most reliable play to get 15 or more points.

I agree, I think the biggest upside is Jackson, but upside with a better floor is Kirk.

Hard to decide cause if Murray is back I would go with Kirk. He has a higher catch rate just doesn’t get the targets he needs