WR2 week 1 (0.5ppr)

I have Diggs locked and loaded as WR 1, but for my WR2 i need to choose between K. Cole, R. Cobb, and J. Gordon. Who should I start as my WR2 and are any of the leftovers worth considering over Marshawn in the flex?

Gordon isn’t a designated starter, Cole did hige things last year for a bit but his role is undefined. Cobb seems like the highest floor, lowest ceiling.