Lucic/williams, they are tier 2/3 players. Keith is a tier 1 who is stuck in the mud down in tier 2. But Frolik and the trade deadline crowds are all bringing fishing poles and sticks to help him out.
If this is a default league with 4 D spots and your other 3 are Letang Ehrhoff Pronger.... Go ahead and dump Keith, but see if you can get seomething slightly more attractive in the tier 1/2 zone. If Keith is you last dying hope for D, keep him.