Police arrested Mickens on March 5 after officers found a concealed firearm during a traffic stop. He was pulled over because the tint on his car was too dark.
The gun charges carry a maximum of one year in jail if convicted.
Mickens played 10 regular-season games and all four postseason games for the Buccaneers last season. He was their primary returner and also played 75 offensive snaps.
The team said in a statement after his arrest that it was monitoring the situation.
Mickens, 27, could face NFL discipline.