Marshawn Lynch and Bruce Irvin helped win a Super Bowl in Seattle before becoming stalwarts in Oakland.
Sebastian Janikowski rewrote the record book for the Raiders before booming long kicks for the Seahawks.
Seattle defensive coordinator Ken Norton Jr. and Oakland offensive line coach Tom Cable spent the past few seasons doing the same job with the other team.
When the Seahawks and Raiders kick off in London on Sunday, it will be a reunion of sorts — even though the game will be played several thousand miles from home.
"I've always enjoyed the most playing against the people I like the most.