Haven't come up with a full list of sleepers yet...But there's a few people on the radar....
With Dwayne Bowe holding out, Jon Baldwin has been having a good camp, and I saw flashes of good things last year.
Isaac Redman from the Steelers looks to benefit from Mendenhall not being fully recovered yet...
Everyone is talking about Antonio Brown, considering Mike Wallace's extended contract hold-out and the fact that not many have faired well after lengthy hold-outs (the stats show this as well). However, Emmanuel Sanders should be on your radar as well. Performed okay last year, but he's been hampered by injuries, that being said the Steelers thought he would be the guy behind Wallace, not Brown.
Jacob Tamme, TE for the Broncos, but was with Indy and filled in well for Dallas Clark when he was out. Already has a history with Manning, and we all know how Manning likes his tight ends...
Jacquizz Rodgers, RB for ATL, is going to get more touches this year with Turner slowing down. This is especially true as he impressed last year, with limited playing time and touches.
Thats it, off the top of my head. I'll be back with more once I've finalized my list.