Description Available in: The Frontier Greys were a professional baseball team in the United States. The Greys were a member of the East Division of the Frontier League, which is not affiliated with Major League Baseball. They were a traveling team that did not have a home city or stadium. They were formed by the league in 2013 to replace the departing Road Warriors and maintain an even number of teams in the league. They were disbanded after the 2015 season when the folding of the Rockford Aviators removed the necessity for the team.