Raiders defensive coordinator Ken Norton helped bring linebacker Bruce Irvin to Oakland on Tuesday.
The deal is in place and can be finalized formally Wednesday when free agents can first sign with a new team.
Norton, who coached Irvin in Seattle before leaving to be Jack Del Rio's defensive coordinator with the Raiders in 2015, likely pitched Irvin on being the sidekick of edge rusher Khalil Mack in Oakland's new-look defense.
Quinn was instrumental in Irvin's development in Seattle. The Seahawks drafted Irvin in the first round of the 2012 draft and he had 22 sacks playing a versatile role bouncing between linebacker and defensive end. The Seahawks declined Irvin's fifth-year option for 2016, which prompted backlash from the emotional linebacker.
Del Rio used linebacker Von Miller as a pass-rush specialist and outside linebacker in Denver when the Broncos ran a 4-3 scheme and could have similar designs for Irvin.