None of the actors who played Sisko ever had a goatee.
It was a van dyke.
Useless trivia, but THE LOO SANCTION (sequel novel to EIGER SANCTION) had a character named Van Dyke who was lesbian. Guess the real Trevanian had a little bit of Ian Fleming in him after all.
Same novel had a black bouncer named Petit Noel that Avery Brooks could have had fun playing ... till he was ultimately replaced by the other fella.