Detroit Lions defensive tackle Nick Fairley isn't practicing due to a "medical issue that he's dealing" with, according to coach Jim Caldwell.

Caldwell said Fairley will "be back as soon as he's recovered."

Recovered from what? Caldwell didn't say. He did note that Fairley had a "procedure.

According to the Detroit Free Press, Fairley has been dealing with sleep apnea.

A 2011 first-round draft pick, Fairley didn't have his fifth-year option exercised.

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Aaron Wilson covers the Ravens for The Baltimore Sun