The Detroit Lions have parted ways with Damon Harrison Sr., releasing the veteran defensive tackle today.
The move frees up $6.7 million in cap room, according to overthecap.com, but leaves a hole along Detroit's defensive line with veteran defensive tackles Mike Daniels and A’Shawn Robinson also scheduled to become unrestricted free agents in March when the new league year begins.
The Lions acquired Harrison via trade with the New York Giants midway through the 2018 season. Harrison quickly transformed Detroit's run defense from one of the worst in football to one of the best. He was arguably Detroit's best player upfront through the second half of the 2018 season.
View photos of NFL.com's top defensive tackle prospects attending the 2020 NFL Scouting Combine.

Texas A&M defensive lineman Justin Madubuike (52) waits for the Mississippi State offense to come to the line during the first half of an NCAA college football game, Saturday, Oct. 26, 2019, in College Station, Texas. (AP Photo/Sam Craft)

Oklahoma defensive lineman Neville Gallimore (90) tackled TCU quarterback Max Duggan, left, in the second half of an NCAA college football game in Norman, Okla., Saturday, Nov. 23, 2019. (AP Photo/Sue Ogrocki)

TCU defensive tackle Ross Blacklock (90) rallies his teammates during the second half of an NCAA college football game against Baylor, Friday, Nov. 24, 2017, in Fort Worth, Texas. TCU won 45-22. (AP Photo/Brandon Wade)

Vanderbilt quarterback Kyle Shurmur (14) fumbles the ball as he is hit by South Carolina defensive lineman Javon Kinlaw (3) during the second half of an NCAA college football game Saturday, Sept. 22, 2018, in Nashville, Tenn. Vanderbilt recovered the fumble. South Carolina won 37-14. (AP Photo/Mark Zaleski)
But Harrison, 31, struggled with injuries this past season and wasn't nearly as effective as he's grown accustomed to being. His 49 tackles were the fewest in a season in which he played at least 15 games. Harrison was Pro Football Focus' No. 1 run-stop defender among interior defensive linemen from 2013 through 2018, but dropped down to ninth in that department last season.
He was emotional after the Lions' season finale against Green Bay, telling reporters how difficult the season had been dealing with injuries and less production than he was used to. He said he was contemplating retirement.
With Harrison's release, and the pending free agency of Daniels and Robinson, Da’Shawn Hand, John Atkins and Kevin Strong are the only defensive tackles under contract for the 2020 season from last year's roster. Hand has finished each of his first two seasons on injured reserve.
The team will have over $50 million in cap space and the No. 3 pick to work with this offseason, however.
This year's class of scheduled free agents at defensive tackle include: Chris Jones (Kansas City), Javon Hargrave (Pittsburgh), Jarran Reed (Seattle), D.J. Reader (Houston) and Ndamukong Suh (Tampa Bay), among others.
Auburn's Derrick Brown and South Carolina's Javon Kinlaw are the top two defensive tackles in the draft, but this is a deep group of interior defenders, with players like Ross Blacklock (TCU), Justin Madubuike (Texas A&M) and Neville Gallimore (Oklahoma) likely to hear their names called in the first two rounds of the draft as well.