The Buffalo Bills announced a back-end roster move on Thursday, waiving undrafted rookie free agent defensive back Vernon Kearney and signing free agent wide receiver DeMarco Sampson. A 2011 seventh-round pick of the Arizona Cardinals, the 6'2", 204-pound Sampson made some waves at receiver as a rookie, making the roster and appearing in 12 games. He caught three passes for 36 yards and played some special teams that season, but didn't make the team in 2012, ultimately spending some time with Philadelphia instead. The 27-year-old was a street free agent, but certainly has the athleticism to warrant a look from the Bills; he ran 4.41 with a 35.5-inch vertical jump at his pro day two years ago.