McClellin is uncertain to continue his playing career due to the "cumulative effect of concussions," Mike Reiss of ESPN.com reports. "I'm still staying ready, still working out. I've learned to never say never, there's always a chance that I could still play again, but for now all my focus is on coaching high school [football]," McClellin said.
While McClellin isn't officially retiring, that appears to be a likely outcome for the linebacker, who has sustained five documented concussions over the course of his career. A first-round pick of the Bears in 2012, McClellin has appeared in 66 regular-season games with Chicago and New England, accruing 8.5 sacks. He spent the entire 2017 campaign on the Patriots' injured reserve list with a concussion before getting released in March.