The Seahawks may be interested in trading Sherman. However, I doubt they're looking to trade him to the Packers or any of their other principal NFC rivals.

http://www.cbssports.com/nfl/news/se...on-both-sides/

Sherman ranked 10th among all cornerbacks last season, according to Pro Football Focus, though it’s worth pointing out that he earned the lowest pass-coverage grade of his career. In fact, his pass-coverage grades have declined the past three seasons. Again, this is all relative; Sherman ranked 15th in pass coverage in 2016, just behind Marcus Peters and Patrick Peterson.
He's still good, but probably declining. If he were the player he used to be, I doubt the Seahawks would be looking to move him. Right now Raiders would be the most likely place for him to be traded to.