So says CBSSports.com:

The 33-year-old, 10-year veteran is a locker-room leader who can still play at a high level. He ranked 23rd among all defensive ends last season, according to PFF, and could upgrade a unit desperate to improve its pass rush, even if on a part-time basis. The Eagles have $4.2 million in cap space in ’18 (rank: 31st) and trading Long would free up $3 million: 

https://www.cbssports.com/nfl/news/nfl-post-june-1-trade-candidates-desean-jackson-teddy-bridgewater-among-top-10/