Players like Eddie Royal and Roy Helu are still available to pick up off the waiver wire in many leagues, and they would make great starts at the flex position.
The flex position is utilized in many leagues, but not all. It is a combination of WR, RB and TE.
The flex is usually reserved for players that would usually not start, so picking players up off the waiver wire is fairly common.
Here are the 10 best flex players still available.