Clay, 26, spent the first half of the 2017 season with the Bills, after the team acquired him via trade with Carolina in exchange for CB Kevon Seymour and a 2019 seventh-round pick.
The receiver would appear in four games for Buffalo, but was used sparingly on offense and as a punt returner on special teams.
When the Bills sustained injuries at the cornerback position leaving them shorthanded at the position last October, they claimed a cornerback off waivers and released Clay.
He was then claimed by the Panthers, where Clay was utilized as a punt returner and reserve wideout.