In California, you may be able to go to your primary care physician after a work-related injury, but only if you have healthcare coverage for medical treatment unrelated to work injuries, if you've given your employer written notice before your workplace injury and if your doctor has agreed in advance to treat you for your work-related injuries or illnesses.
If you have not pre-designated your personal doctor, you probably will not be able to choose the initial physician you see for your treatment. When the employer or its insurance company has established a medical provider network or MPN, you will typically choose a doctor from that network.
The exceptions to this rule are when you require emergency medical care and when your employer has not provided you with some legally-required notices and information.