This article lists stats but chart will not copy/paste; must go to link to see or click on second link and pull out individual WR
As it turned out, they should have been more worried about how to replace Jacoby Jones.
Garrett Graham stepped in at tight end and managed to replicate Dreessen quite well. He wasn't as explosive on a per-catch basis, but his catch rate was virtually identical.
Where the Texans suffered was in replacing Jones.
(Table of stats)
Jones was released after the 2012 draft in what proved to be a colossal mistake. Not only did he have a standout season on special teams, making the Pro Bowl for the AFC, but the Texans had no way to replace his modest production in the passing game.
Full NFL results here http://www.footballoutsiders.com/stats/wr