"There has been subsequent evaluation and consultation regarding Jahvid since our last update," Lions general manager Martin Mayhew said in a statement. "As has been the case throughout, we have deferred to the medical experts and support their current recommendation that Jahvid not return to the field this season.
"Javhid's approach to this situation and his adherence to the process and protocol have been exemplary. No one has worked harder or shown more dedication than Jahvid has over the past year. As disappointing as this decision is for us and Jahvid, we do believe it is in his long-term best interest."
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Best hasn't played since October 2011, when he suffered his second concussion in three months. Best has had concussion issues dating back to college, when a frightening crash to the turf cut short his junior season at California. That injury scared off some NFL teams, but the Lions still made him the 30th overall pick in the 2010 draft.
This must be upsetting for Best, who's made it clear he'd like to get back on the field. But considering the back story, this is probably the best thing that could happen to him.