Caussin hadn't played in a game for the Bills since December 2011, spending all of last season on the physically unable to perform list, but he would have been in the mix for a roster spot this preseason if healthy.
Instead, the Bills will continue to lean on Lee Smith, a fifth-round choice of the New England Patriots in 2011 who has settled into a role with the Bills, starting seven games last season. At 6-foot-6, 265 pounds, Smith is known as a hard-nosed blocker, but has caught just eight passes in two NFL seasons.
The Bills have an emerging threat at tight end in veteran Scott Chandler, who had 43 catches and six touchdowns in 2012 before a torn ACL ended his season in late December. Just eight months removed from surgery, the Bills have eased Chandler back into action during training camp.
Head coach Doug Marrone said that Chandler will likely play in Friday's preseason game against the Minnesota Vikings, but even with Chandler on pace to start in the regular season opener, it's surprising that the Bills did not bring in another tight end this offseason as insurance.
While the Bills anticipate using three-wide receiver formations frequently and making use of their running backs in the passing game, another injury to Chandler could limit the Bills offense.
Beyond Smith, the Bills' options at tight end are Dorin Dickerson, a converted wide receiver with limited NFL experience, and a pair of first-year players: Chris Gragg (seventh round) and Nick Provo (undrafted). At this point, all are back-end roster or practice-squad level players.
The Bills have a first-year general manager in Doug Whaley who will need several seasons to develop depth across the roster, an important component for any team over the rigors of a 16-game season. But right now, it's not hard to imagine that tight end is one position where the Bills know they are thin.