Restricted Work Release/ Non-Workman Comp.

If a person is injured off the job or has had surgery for an unrelated work incident does the employer have to let that person return to work if the doctor has not given a full release? Our company policy has been that a person has to be fully released with no restrictions. I live in Oregon--is there any state laws requiring the company to let a person return to work if they are restricted with what they can do or the hours they can work?