The Scorpions, who were ranked 143 in the world in September, are placed at 161 in the global stage.
The Gambia have also dropped down 3 places in the continental ranking, moving down from its September ranking of 43 to 46 in October.
The Scorpions will host Namibia in the preliminary round of FIFA World Cup qualifiers on Friday 9 October 2015 at the Independence Stadium in Bakau with their opponents ranked 125 globally and 37 in Africa.
