The actor is set to play a recurring role as the right-hand man to Harold Perrineau's character, reports Deadline.
Perrineau was previously cast to appear as an ex-drugs kingpin named Damon Pope, whose daughter was killed by Tig in the season four finale.
Brown's television credits include Dexter, Southland and Dirt.
Last year, the FX series was renewed for a fifth season along with a sixth and seventh run.
Sons of Anarchy creator Kurt Sutter previously revealed his interest in making a prequel series.
He said: "I see it as a different show. Not a continuation or another version of Sons of Anarchy but a more political and socially historical sort of show."
Watch a season four promo for Sons of Anarchy below: