Barwin, 32, signed a two-year deal worth $3.5 million right before the start of training camp last summer. His professional approach and strong locker room presence were factors in the acquisition.
The parting of ways was a mutual decision. Barwin would still like to play and the Giants save $1.5 million against the salary cap with the move. They take a $365,000 dead-money hit on the 2019 books.
The early decision allows Barwin time to explore his options.
"It's obviously got to be a situation where I play," Barwin told NJ Advance Media after the season. "So, we'll see what happens. I started five games when [Olivier Vernon] was out, and then essentially didn't play until the very end. I played against the Bears when Lorenzo [Carter] didn't play, but then I played token six snaps. I have a little more left than that."
Barwin's playing time decreased greatly as the season progressed. He started three of the first five games this season with Vernon sidelined by an ankle injury. But he rarely saw the field later in the year. Barwin was on the field for more than 10 snaps just four times over the final 11 games as the Giants leaned more on younger players such as Carter, a third-round pick last year out of Georgia.
It was the first season since 2012 that Barwin finished with fewer than five sacks.
Barwin originally was a second-round pick by the Houston Texans out of Cincinnati. He has 56.5 career sacks in 142 games with the Texans, Eagles, Rams and Giants.