Wisconsin Woodchucks officials learned the three were at a party where a cat was injured and eventually died.
Neighbor Gary Trembath says he was told the cat was run over, but he says the animal wasn't found near a road.
The owners of the Wausau home are hosting a Woodchucks player for the summer and were out of town Saturday night.
The Wausau Daily Herald says the cat was found bleeding in the family's yard before some players took it to a vet, where it died.
The owner of the Woodchucks, Clark Eckhoff, says the incident warranted strong action from the club, but he wasn't more specific. Eckhoff said the three suspended players include pitchers Steve Grasley and Adam Rowe and infielder Scott Koeber.
Grasley is a junior at Creighton University in Nebraska. Rowe is a junior at Mount Vernon Nazarene University in Ohio. Koeber is a junior at Michigan State.
The Woodchucks are playing in the league's championship series this week. Wausau police are not investigating the incident.