Best hasn't played since he was knocked out of a game against the San Francisco 49ers on Oct. 16, 2011, with what he has said was his third concussion.
"For the past year he has endured countless hours of cognitive rehabilitation and therapy with enthusiasm and eagerness without complaint anger or impatience," Lions athletic trainer Dean Kleinschmidt said. "I have never pulled harder for an injured athlete to return to the field of play."
Detroit drafted Best in the first round in 2010 and he accounted for 1,000-plus yards and six touchdowns. Best was limited to six games last season and is hopeful he can make a comeback next year.
He hadn't spoken publicly since the team announced earlier this month that he would stay on the physically unable to perform list for the year.
"They told me I can't play this season, but they didn't shut the door," Best told the crowd. "I'm a glass-half-full kind of guy. If you don't shut the door, there's still a way."
Best said he feels "normal" when he wakes up each day, but understands why he hasn't been cleared to play.
"Especially this year with the way they are about concussions and how sensitive a subject it is right now, they just want to make sure everything is OK," he said. "We're just taking the safest approach."
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