Should I give up Mack or Bell in this trade

Trade Away:
J. Winston
L. Bell or M. Mack

M. Ryan
T. Hill

.5 PPR

My team:
QB: J. Winston (used to have Brees)
WR: J. Edelman
WR: A. Robinson/M. Brown
RB: L. Bell
RB: M. Mack
TE: T. Kelce
Flex: D. Singletary/T. Coleman/C. Samuel

IR: Guice