What It Means:

A San Diego Chargers washout after signing a massive contract, Butler made it about six weeks on the Arizona Cardinals' roster this summer. Still only 27, Butler has lots of talent, but was widely accused of quitting on the team in San Diego. The Dolphins will assess if he's a lost cause, at no risk. Miami has an improved linebacking corps, but one that could still use depth.

Butler has sustained some injuries in his career, but still was on a full-season pace for 95 or more tackles in each of his first three seasons in the NFL. The Dolphins defense ranked 30th in Defensive Adjusted Net Expected Points per play last season, but has gotten off to a hot start in 2016, ranking seventh after Week 1.