Two leagues. First is 14 team PPR with two flex (RB/WR/TE): Decent balance b/w RBs and WRs. Drop Khiry Robinson for Andrew Hawkins? 2nd 12 team non-PPR, one flex (RB/WR/TE): Stronger on WRs than RBs. Drop Wheaton for Telaferro/Sankey?
1st: I wouldn't but let's see what @Greg Brosh says 2nd: that is a tough one. But It depends on your roster, can you post your rosters in the signature so we can help you more?
Robinson is going to be playing for at least a few more weeks. Only way I drop him is if you have 3 strong backs and really need receivers. I won't answer the 2nd. Post both rosters. That will help a lot.