Fielder Positions

[drwells1]

Hey guys got a question for ya'll. It is probably an easy answer but I can't find anything in the ASA book about this. I am doing mens slow pitch last night and the team at bat is place hitting like crazy. The defense decides to bring one of the outfielders in and he stays in the dirt on the edge of the grass but clearly in the infield. Is this legal? I asked my partner who was the plate umpire if he knew if it was legal or not and he thought it was not but couldn't be sure. Like I said I should know this but can't find any clarification. If ya'll could give me refernces it would be appreciated.