One of the major weaknesses of the 2017 New England Patriots was the team's depth at the linebacker position. With both Dont'a Hightower and Shea McClellin out for the year, the team was unable to consistently defend the middle of the field against both the pass and second-level runs. While Hightower's loss was the bigger one due to his versatility and playmaking abilities, McClellin's also cannot be underestimated.
The former first round draft pick missed the entire season due to a series of concussions. Despite his recent injury history, however, McClellin intends to continue player (according to the Boston Herald's Jeff Howe):
Despite suffering a couple concussions that wiped out his 2017 season, Pats LB Shea McClellin does intend to continue playing, per source.