Fanene, 30, was a pricey offseason signing, with the Patriots inking him to a three-year, $9.85 million contract in free agency and giving him a $3.85 million signing bonus. A knee injury forced Fanene to miss the team's last 13 practices, though, and according to one report, he might soon need arthroscopic surgery on his knee. The former Cincinnati Bengals defensive end posted a career-high 6.5 sacks last season.
Hill, 23, was signed as a rookie free agent earlier this month after being a four-year starter at Duke.
Koepplin, 26, was signed during the spring. This was the second straight season in which Koepplin, who kicked at the University of Massachusetts, participated in Patriots training camp. The team cut him last season on Aug. 29, 2011.