The two 18 year-olds, and one 19 year-old, had amassed gas pistols, balaclavas and stolen number plates and were on their way to the casino before changing their minds.
On the way back, police noticed the stolen number plates and pulled the trio over.
After a search of the car and interrogation the group admitted to their plan to police.
Hannover was informed of the incident and immediately suspended them.
The names of the players have not been released.
Speaking to Spiegel Online a club spokesperson confirmed the incident, while a police spokesperson also confirmed the matter to Bild.
