Financial terms were not disclosed but a source told ESPN's Adam Schefter that the deal is worth $11 million.
The deal brings Harrison's guaranteed money to $12 million between the 2019 and 2020 seasons, according to Schefter. Harrison had been under contract through 2020 -- initially making $6.75 million in 2019 and $9 million in 2020.
Now his deal runs through 2021, although it is still unclear how the money will break down between those three years.
Thank you everybody and thank you Detroit! The continued support didn't go unnoticed from Lions fans all year. I appreciate you guys and my family and I are excited to be continuing my career as a Lion. Huge thanks to BQ, Coach P, Rod, and the Ford family! #SnacksSZN8 💪🏾🗣— Damon Harrison Sr. (@snacks) August 22, 2019
Harrison had been seeking a contract extension from the organization, which acquired him in a midseason trade last year with the New York Giants for a fifth-round pick. Harrison sat out all of the spring workouts -- including mandatory minicamp -- this offseason, at least in part over his contract status.
The 30-year-old Harrison was then placed on the non-football injury list to start training camp before starting to practice last week in Houston. He has yet to speak to the media this preseason.
Harrison is a key part of Detroit's defensive line as one of the top run-stoppers in the league. He has played in 102 games, starting 95 of them -- including playing in 17 games last season. He has nine sacks and four forced fumbles in his career, but the 350-pound tackle is dominant against the run. Pro Football Focus graded him as the No. 3 interior defender in the NFL last season and said he had the best run-stop percentage in the NFL (16%) last year.
A first-team All-Pro in 2016, Harrison went undrafted in 2012 out of William Penn in Iowa and then spent four years with the New York Jets and two and a half years with the Giants before being traded to Detroit.