Sebastian Janikowski has in fact taken a pay cut. The Raiders kicker’s salary has gone from $4.05MM to $3MM fully guaranteed, a source tells ESPN.com’s Adam Schefter (on Twitter). As a part of the revised deal, however, Janikowski can make an additional $250K if he sinks 83% of his field goals. 
On late Wednesday night it was reported that Janikowski had resolved his “contractual differences” with the team. Unsurprisingly, that included a bit of a hair cut for the veteran kicker.
The Raiders auditioned kickers Mike Nugent, Josh Lambo, and Marshall Koehn on Labor Day and Lambo in particular was said to have excelled. Meanwhile, Janikowski was missing kicks in practice thanks to his bad back. The Raiders may or may not have been serious about the idea of cutting ties with their longest tenured player, but either way the tryouts gave them the leverage they needed to save some money against the cap.
Last year, Janikowski made 82.9% of his field goals and went 37-of-39 on extra point tries. He has not cleared the 83% mark on field goals since 2014.
Of course he did. It was either that, or be shown the door.