Here's one worth monitoring.
Cecil Shorts. Earlier this spring, it seemed as if JAX wanted Gabbert to win the QB job. He has struggled and is now hurt and will lose some practice time. Henne is, at best, a back-up QB, but likely as good if not better than Gabbert and now has a chance for more reps. Shorts clicked much better with Henne than Gabbert. Tossing the games where both QBs had at least 10 attempts (without digging deeper, I have no way to differentiate who did what wrt to Shorts), Shorts played 7 games with Gabbert as the primary QB and 5 games with Henne as the primary QB. With Gabbert, Shorts averaged (per game): <4 target, <3 receptions and ~54 yds. He also totaled 2 TDs with Gabbert (~0.3 TD/g). With Henne as the primary, Shorts averaged >9 targets, >5 rec and ~ 84 yds. With Henne, Shorts scored 3 TDs (0.6 TD/g). On the plus side, Shorts finished strong with Henne and is entering that mythical third year as a pro WR, and the way it looks now, Henne will be the starter. On the down side, Shorts had 2 concussions at the end of the season and finished on the IR, so there is some injury risk.
I am not sure if a 2nd year WR that put up 979 yards and 7 TDs constitutes a "sleeper" per se, but his current late 7th round (12-team) ADP and the 33rd WR off the board looks interesting given the potential upside - I'd rather have him than several WRs taken a full round-plus ahead of him (eg Decker, Austin).