A No. 2 overall draft pick by the Rams in 2008, Long spent eight seasons with St. Louis before he joined the Patriots in 2016.
Long has 342 tackles, 58 1/2 sacks, nine forced fumbles and six fumble recoveries in 130 games.
He had four sacks and 10 quarterback hits in 16 games for New England and was an integral part of a defense that allowed an NFL-low 250 points.
Later Tuesday, the Eagles agreed to terms on a one-year contract with cornerback Patrick Robinson.
Originally a first-round pick (32nd overall) of the Saints in the 2010 draft, Robinson has played in 81 regular-season games with 49 starts and has 260 tackles, 10 interceptions, 59 passes defensed and three forced fumbles. He spent his first five years in the NFL in New Orleans before playing for San Diego in 2015 and Indianapolis last year.
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