The Arizona Cardinals cut Butler on Saturday in order to help trim their roster to 53 players. He appeared in 13 games for the Dallas Cowboys in 2017, catching 15 passes for 317 yards and three touchdowns.
The Raiders cut Martavis Bryant on Saturday, a little over four months after acquiring him from the Pittsburgh Steelers for a 2018 third-round draft pick. ESPN's Dan Graziano reported Bryant violated the NFL's substance-abuse policy and is thus subject to a pending suspension.
According to NFL Network's Ian Rapoport, the Raiders signed Brandon LaFell to a one-year contract Monday, which would seemingly fill the void created by Bryant's departure.
However, the Las Vegas Review-Journal's Michael Gehlken wrote Oakland "need[s] more speed" in its receiving corps, which the Raiders are "expected to address soon."
Butler is averaging 16.1 yards per reception through his first five years in the league, and he averaged 21.1 yards per catch in his final season with the Cowboys.
Oakland opens the regular season Sept. 10 at home to the Los Angeles Rams. That leaves the Raiders with little time to waste in terms of potentially signing Butler and getting him ready for Week 1 if he's their preferred target.