Trying to think of the possible hands we could put him on here, I'd say it's fair to say that the grinder probably wouldn't just call from the button with K4, K2, or K8. Since from the button he would also probably re-raise with AK to weed out the SB and BB, we can eliminate AK as well. AA and KK are possibilities since he could have been trapping, and there was nothing too scary on the flop to halt that strategy. 88 isn't much of a possibility either, since it's probable that he would have played that on the flop. 44 or 22 are the other hands he could have since they would not have been bad c