Long, who turned 32 on Tuesday, recently announced he wasn't returning to the New England Patriots after winning a Super Bowl ring in his lone season with the team.
He explained his decision on a post on Instagram.
"This has zero to do with money, etc.," Long wrote. "It's the right move in my heart because I want to get back to being the player I was before. I'm thankful for my role this year, but as a competitor, I'm itching to do what I do best."
Long posted four sacks for the Patriots last season and has 58 1/2 in his career. His best outputs were when he had 13 sacks in 2011 and 11 1/2 in 2012 as a member of the St. Louis Rams.
Long played his first eight seasons with the Rams before joining the Patriots last season. He was the second overall selection of the 2008 NFL Draft.