Flex Help! Playoffs

I am currently trying to decide who to put in my flex.
Options are:
Stefon Diggs
Josh Gordon
Semaji Perine

I am leaning towards Perine, your input would be much appreciated.

I’d hate to trust Perine but Redskins are favored by 4. He’s the only one in their backfield. We can only hope he gets fed enough.

I don’t feel great about putting Perine in there, but I also don’t feel great about the matchups for both Diggs and Gordon.