The news came out via Adam Schefter Thursday morning that the Cardinals had restructured the contract of Chandler Jones this week in order to clear an extra $4 million in salary cap space.
(As a quick reminder, restructuring essentially means the player gets more of his money now in the form of a bonus instead of somewhere later in the contract. That allows the bonus money to be spread out for the duration of the rest of the contract, lowering the current salary cap hit.)
According to the NFLPA site -- which may or may not have already added in the extra $4 million -- the Cardinals are at $7.39 million in current cap space. The news fueled the idea that the Cardinals may have an imminent move. (I've noted on Twitter I don't think the Cards are a potential Jalen Ramsey landing spot, even though Schefter reported the Cards did inquire.)
UPDATE: As of Friday morning, Steve Keim said the Cardinals had sunk to less than $1 million in cap space, meaning the Jones move was needed.
I don't know about anything imminent. But there is always the chance the Cardinals could be working on potential moves at some point and know they'll need the room.