"I know there's a lot of information out there right now as far [as] a potential trade between us and the Giants," Lions coach Matt Patricia said Wednesday before the trade was finalized. "I know a lot of that is out there, but unfortunately, for myself, I'm not going to comment on any situation that is not official or is not complete."
The deal comes less than 24 hours after New York traded starting cornerback Eli Apple, a former first-round draft pick, to the New Orleans Saints for a fourth-round pick in 2019 and a seventh-rounder in 2020.
Harrison and Apple may not be the only players dealt away by the Giants (1-6), who are mired in last place in the NFC East.
League sources told ESPN's Jordan Raanan on Tuesday that there is an impression around the NFL that anyone on New York's struggling defense could be available in a trade.
The Giants also waived struggling offensive tackle Ereck Flowers, another former first-round pick, earlier this month.
Harrison, in a series of tweets later Wednesday, bid farewell to the New York-New Jersey area, where he has spent his entire seven-year career with the Giants and Jets.
Goodbye New Jersey...I gave everything I had. Y'all be good https://t.co/7yeR5hsgTn— Damon Harrison Sr. (@snacks) October 24, 2018
Much love to my teammates, the amazing staffs, coaches, and all the fans. This is my second home because of you...✌🏾 pic.twitter.com/4VUAjkIHlu— Damon Harrison Sr. (@snacks) October 24, 2018
Detroit what up????— Damon Harrison Sr. (@snacks) October 24, 2018
The 355-pound Harrison should strengthen a Detroit run defense that ranks 30th in the NFL while bolstering a defensive line that has been without star pass-rusher Ezekiel Ansah for the majority of the season because of a shoulder injury.
But Harrison also comes with a hefty price tag; the Lions will be on the hook to pay the remaining $4.1 million he is owed this season, plus $7 million in 2019 and $9.25 million in 2020. Harrison signed a five-year, $46.25 million deal with New York before the 2016 season.
Harrison, who turns 30 next month, has 31 tackles and one forced fumble in seven games this season. He was selected to the Pro Bowl in his first season with the Giants in 2016 and has recorded 386 tackles and 5.5 sacks in 92 games -- 86 starts -- over parts of seven seasons with the Giants and Jets.
Second-year pro Dalvin Tomlinson and rookie B.J. Hill are likely to handle the Giants' interior defensive line spots, backed up by veterans Josh Mauro and John Jenkins. Rookie RJ McIntosh has started practicing after spending the season on the non-football injury list.
The Lions (3-3) are within striking distance of the first-place Vikings (4-2-1) in the NFC North but have the NFL's 24th-ranked scoring defense, allowing 26.3 points per game, and have yielded 139.3 rushing yards per game.
To make room on their roster for Harrison, the Lions cut veteran defensive tackle Sylvester Williams. Williams, a Denver Broncos first-round pick in the 2013 draft, was in his first season with Detroit.
ESPN's Michael Rothstein contributed to this report.