The Jaguars need Thompson for depth since starter Alan Ball (biceps) has been ruled out for Sunday's game against Miami and fellow cornerback Dwayne Gratz is listed as questionable with a hip flexor injury.
Thompson would back them up. He spent the first seven weeks of the season on Jacksonville's practice squad. An undrafted rookie in 2012, he has spent time with Atlanta, Washington and Chicago.
King was inactive for five games after Jacksonville signed him off Carolina's practice squad.
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