Flames centre Derek Ryan also cleared waivers.
Simon, 26, has been a healthy scratch for five straight games and has no points in eight games this season.
Filppula, 36, was scratched on Tuesday against the Columbus Blue Jackets to make room for AHL-callup Michael Rasmussen to play. He has five points in 20 games this season.
Geertsen, 25, has yet to play in the NHL but has skated in four games for the Rangers' AHL affiliate, the Hartford Wolfpack, this season.