Spikes had fallen out of favor with the team, while Fletcher played primarily on special teams and in sub defense, logging just over 18 percent of the defensive snaps during the regular season.
With both out of the picture, the Patriots now have just three linebackers on their roster who played more than a single defensive snap last season. Jerod Mayo, who will return from a torn pectoral muscle, Jamie Collins and Dont'a Hightower project as starters in base defense, but the Patriots have little established depth behind them.
Steve Beauharnais, Chris White and Ja'Gared Davis all are on the roster as well, though each was a core special teamer in 2013. With that in mind, linebacker has become a position for the Patriots to address this offseason.
The team recently had Wesley Woodyard in for a visit, but he wound up signing with the Titans.
The starting trio is a solid cast, with Collins expected to improve from his rookie to sophomore season, but the Patriots now need to consider adding at least one more body to their linebacker rotation for 2014, be it through the draft or free agency.