Sweeney has been seeing looks with the first team, as three other tight ends are working through injuries, Nate Mendelson of the Bills' official site reports.
Sweeney, a rookie seventh-rounder out of Boston College, may have originally been a question mark to make the team, but several injuries have pushed him up the depth chart. Right now, he's the top pass-catching tight end in camp. Tyler Kroft (broken foot) is expected back somewhere around the start of the regular season, while fellow rookie Dawson Knox (hamstring) probably will be back sooner. Lee Smith is locked in with a roster spot but primarily is a blocker. As of now, Sweeney probably has the edge over Jason Croom (hamstring) if only because he's healthy and the Bills can only afford to carry so many injured guys.