Bennett thanked the Seahawks organization in an Instagram post Wednesday evening.
Dear Seattle, #12s, You have meant so much to me and my family! I thank you from the bottom of my heart. First and foremost I want to thank my wife and family, for always supporting me and helping guide me in every situation. My wife is the backbone of our family and I am truly blessed to have her and our three daughters. I of course want to thank Paul Allen, Pete Carroll, John Schneider, Peter McLoughlin, Erik Kennedy and Mo Kelly for bringing me to the Seahawks and giving me the opportunity to help bring Seattle their first Championship. My teammates. My brothers! More important than any championship or ring are the relationships I have made with the men in that locker room. We experienced marriages, births, deaths, and everything in between, and those are moments I will cherish forever. Last but certainly not least, to the City of Seattle, one of the best in the world. You fans are world class. The way you support us players on and off the field, helping to build bridges across our communities and understand what it means to give back and be community-minded. I am forever grateful for allowing me to grow and evolve in this time that I've had with you. I expanded my family in this city, I had one of my babies here. This truly was home for us and it's been such an incredible five years. I want to assure you that the work we have started here with The Bennett Family Foundation will not stop. We are committed to this city, community and the schools we serve. It's been a blessing to be able to meet so many great people through our work, and share our passion and dedication to better the World, and we look forward to meeting so many more of you. We are just getting started. We thank you, we love you, God Bless! Love, Black Santa
Johnson, who has run the 40-yard dash in 4.36 seconds, gives Seattle insurance if it loses speedy wide receiver Paul Richardson in free agency.
The addition of Bennett will allow the Eagles to explore a potential trade of defensive end Vinny Curry.
Curry paced the Eagles with 41 hurries in 2017 but finished with just three sacks. He carries a cap hit of $11 million in 2018. The Eagles were working to restructure Curry's contract in an attempt to keep him, but the arrival of Bennett is likely to accelerate trade talks.
That might not be the only other shoe to drop. The Eagles were projected to be around $9 million over the cap before this deal and will have to make moves between now and March 14 to ensure they are cap-compliant.
The trade can't be officially announced until March 14, when the 2018 league year begins.
Bennett, who sat during the national anthem last season to protest social issues, enters an organization that has been accepting of social advocates on the team.
Safety Malcolm Jenkins is a co-leader of the Players Coalition, which joined in a partnership with the NFL that calls for the league to contribute $89 million over seven years to projects dealing with criminal justice reform, law enforcement/community relations and education. Jenkins, defensive end Chris Long and wide receiver Torrey Smith have been some of the more active players on the social justice front. Jenkins demonstrated during the national anthem for a season-plus before the Players Coalition's partnership with the NFL was announced in late November.
Trading Bennett clears around $2.2 million in 2018 cap space for the Seahawks, though he'll carry about $5.2 million in dead money charges. By trading him before he was owed a $3 million roster bonus on March 18, Seattle also will save $21 million in cash over the remaining three seasons of his extension that he signed in 2016.
The Seahawks now have four picks in the fifth round and two in the seventh, still leaving them with eight in all but none in the second or third rounds.
Bennett was second on the Seahawks with 8 1/2 sacks in 2017 and again led the team's defensive linemen in playing time by a wide margin. But there were doubts about his future in Seattle, as he will turn 33 in November and dealt with knee injuries and a torn plantar fascia in his foot during the season.
"With me, I'm fine. I mean, whatever happens, I've loved being a Seahawk," Bennett told reporters on Jan. 1. "... You love the organization. You love the players that you played with. We've won a lot of games. So if I am not here, I would never have any hard feelings toward the organization. I love [coach] Pete Carroll and [general manager] John Schneider, and we just move forward. It's part of football."
Bennett entered the NFL as an undrafted free agent with the Seahawks in 2009 but spent the majority of his first four seasons with Tampa Bay. He returned to Seattle as a free agent in 2013 and produced 39 sacks over his five seasons with the team. He was named to the Pro Bowl in each of the past three seasons and was a member of Seattle's Super Bowl XLVIII championship team.
ESPN's Dianna Russini, Tim McManus and Brady Henderson contributed to this report.