Flex help: Boston or Downs?

Full PPR. My opponent already has 86 points from Bijan, London, and watson from Thursday game. Thinking I gotta start Boston to swing for the fences. Been rolling with Tuten in the flex but not much of a ceiling it seems like. Rest of my team is:

Hurts @ chi

Gibbs vs NYJ
Kyren @ DEN

Nabers vs TEN
M. Golden - 21 points (thurs)

T. Warren vs HOU

__flex?________

T. Loop @ DAL
49ers DEF vs ARI

Bench:
Downs vs HOU
Boston vs CAR
Concepcion vs CAR
Doubs @ JAX
Tuten vs NE
C. Williams (out)