Redraft: Cooper or Lockett (Return Yards)

[Kramer]

So this is a 12 team full PPR redraft league with a point for every 20 return yards. Starting requirements are QB/2RB/3WR/TE/Flex/Def/K. My team is as follows:

QB: Tyrod, Luck
RB: Bell, Zeke, Duke, Powell, McFadden
WR: DT, Diggs, Alshon, Lockett
TE: Gronk, Graham

So I have a pretty solid team and am 4 - 0 so far. Got an offer where I give up Lockett and I get Cooper. Is this a slam dunk accept? Or is there enough of a cause for concern with Carr's injury, Cooper's drop issues, Lockett's added value in return league? Thanks for any advice.

[Slackalacker]

Lockett has minimal value in seattles passing game, I expect even a poor performing Cooper to outscore him in WR value and be close enough in return value to want Cooper over Lockett.