Diggs had been a starter for the Lions since 2017 at slot cornerback and safety. Over the past two seasons he had become one of Detroit's most reliable players in the secondary, along with Pro Bowl cornerback Darius Slay.
Diggs, 26, was a Pro Bowl alternate last year after a 78-tackle, three-interception season with eight passes defended. This season, he missed one game and part of another due to a hamstring injury, but had been on the field for a high percentage of snaps otherwise.
He wasn't playing as well as he did in 2018, but still had 20 tackles through five games for the Lions.
In an Instagram post Tuesday night, Diggs thanked his former Lions teammates and expressed excitement over his new team, writing, "Seattle let's get it!! Ready to get to work and win more games!! Too hyped!!"
The Seahawks already have a logjam at safety, although starter Bradley McDougald is dealing with back spasms that kept him out Sunday against Baltimore and Lano Hill is expected to miss at least another week with an elbow injury. Rookie second-round pick Marquise Blair impressed coach Pete Carroll on Sunday while making his first career start. Free safety Tedric Thompson, meanwhile, allowed a 50-yard completion on Baltimore's first possession that Carroll lamented as a "big mistake."
"I hate that we gave them that," Carroll said. "There's no way that should ever happen."
Detroit does have an abundance of safeties to use with Walker. Besides Harris, both veteran Tavon Wilson and rookie C.J. Moore could see more work in the defensive backfield, particularly in nickel and dime packages.
But moving on from Diggs makes this the second consecutive season in which Detroit traded a player who was popular in the locker room and with fans. Slay was among Lions players to react on Twitter, calling the trade "bulls---" in one of his tweets. Running back Kerryon Johnson, who was placed on injured reserve earlier Tuesday, also weighed in.
This one hit me bra😢 https://t.co/coKjDwUrTq— Darius Slay (@_bigplayslay23) October 22, 2019
Well this has been a tough day personally....my dawg...imma miss the hell out of you @qdiggs6— Kerryon Johnson (@AyeyoKEJO) October 22, 2019
Nooooooooooooooooo— Mal (@jamalagnew) October 22, 2019
Wowwwwwwwww no way— Damon Harrison Sr. (@snacks) October 22, 2019
Last year at the trade deadline, the Lions sent Golden Tate to Philadelphia for a third-round pick. Tate returns to Detroit on Sunday to play the Lions with his new team, the Giants.
Unlike Tate, Diggs was not in the final year of his contract when Detroit traded him. Diggs signed a three-year, $20.4 million extension last season. He is under contract until 2021 and has cap hits of $6,991,666 in 2020 and $7,341,668 in 2021, but no guaranteed money in either season.
Lions coach Matt Patricia said Wednesday that despite trading Diggs, the Lions still have all their short-term goals intact. He admitted it's a "hard balance" making decisions while you're building a team on decisions in the now versus the long term, but they are trying to do everything they can to win.
And Patricia believes in the depth the Lions have at safety without Diggs.
"Those guys in the back end have all really been working hard and developing, and some of those guys have had to really play in the last couple weeks and in some of those bigger games we've had so far this year," Patricia said. "Will Harris has certainly had to step into some roles. Tracy Walker plays more for us in some of those roles. Tavon Wilson, who has been a good, solid player for us for a long time.
"C.J. Moore, you'll see him; he's been mixed out there too in some of these games. ... We have some depth, too, with some guys who have played for us in the past; [Miles] Killebrew would be another one. Those guys, they'll continually push to get better and they understand that maybe they have to take on a little bit more of a workload or job responsibility or whatever it is. I think they are good with that challenge and accept that challenge and go forward from there."
ESPN's Brady Henderson contributed to this report.