Dykstra, 50, who had a 12-year career with the New York Mets and Philadelphia Phillies, was freed, according to federal Bureau of Prisons records, but no other details were available. A message left for his attorney Christopher Dybwad was not immediately returned Friday.
Dykstra was sentenced in December to 6 1/2 months in prison for hiding baseball gloves and other heirlooms from his playing days that were supposed to be part of his bankruptcy filing. He already had served seven months in custody awaiting sentencing.
The prison term ran concurrently with a three-year sentence for pleading no contest to grand theft auto and providing a false financial statement.
Dykstra, who bought a mansion once owned by hockey star Wayne Gretzky, filed for bankruptcy four years ago, claiming he owed more than $31 million and had only $50,000 in assets.
After the filing, Dykstra hid, sold or destroyed at least $200,000 worth of items without the permission of a bankruptcy trustee, prosecutors said.
He pleaded guilty last summer to one count each of bankruptcy fraud, concealment of assets and money laundering.
Dykstra is now on three years' probation and must complete 500 hours of community service, participate in a substance abuse treatment program and pay $200,000 in restitution.