As Doug Kyed of NESN noted, no offer sheet has been extended, and the transaction allows the team to discuss trades.
This removes the opportunity for Butler to sign as a free agent with another organization.
In March, Michael Giardi of CSN New England reported Butler was "frustrated" by the Patriots' position and wanted to play elsewhere. Albert Breer of The MMQB said in April it was "more likely" Butler would end up in New Orleans than New England, via CSN New England.
The 27-year-old Butler—who went undrafted following a standout career at West Alabama—has spent the first three years of his career in New England, starting every game in the last two seasons. He was named to the Pro Bowl in 2015 and has helped the Patriots win two of the last three Super Bowls, famously grabbing the game-sealing interception at the goal line against the Seahawks in Super Bowl XLIX.