Watching the NFL it is very evident to me that one area the Steelers sorely lack is a physical WR. Brown and Wallace while burners, are just not WR's who can muscle up CB's and make back shoulder or in traffic catches. Sanders looks tentative when running anything in the middle of the field. Cotchery was barely a blip on the radar screen.
When I watch AJ Green, Brandon Marshall, Dez Bryant, Calvin Johnson, Larry Fitzgerald, Aquan Bolden, Demaryus Thomas, etc and that physical nature of the WR play is lacking in our current crop of WR's. To me, With the exception of Heath Miller the Middle of the field has become a void to the Steelers offense. (i have no statistical basis, just an observation)
Though he had slipped towards the end, Hines Ward made up for his lack of size with a physical style of play and a fearlessness to own the middle of the field, that in my opinion is sorely missing right now. The Steelers did not replace Hines production from the slot. How many catches can you remember Hines making going up holding on to a pass on a 3rd and 6 and getting smashed by a Safety or LB. For his career 62% of his catches went for First Downs and that had to be a security blanket for Ben.
This is a non expert opinion but its as if Ben's Hot reads on blitzes are being bumped off routes way too often. Understand, I realize Hine's time had come and gone but it seems as if that area was sorely missing.
Again just my opinion.