Meridian Officer Eric Johnson was recorded on video Friday, fighting at a Ridgeland park with a coach from another team.
Local media report the other coach, Leroi Gray of Clinton, had been ejected from the game but continued to argue with Johnson. The two then began fighting.
Gray was hospitalized with a broken leg, and filed assault charges Wednesday. Ridgeland Police Chief John Neal says Johnson has agreed to turn himself in to comply with an arrest warrant issued Thursday.
Meridian police had placed Johnson on leave.
Meridian Mayor Percy Bland, whose son was playing at the baseball tournament, was among bystanders who tried to break up the fight.