California  |  Workers Comp

I was injured at work but did not have to miss ant time due to the injury. The doctor provided by my work is about 115 miles round trip from my home and each time i've visited their office they tell me they can't really determine the extent of the injury and that although it's not causing me trouble now it may turn into a problem later. So each month I have to drive the 115 miles to the designated physician so he can tell me the same thing. The main problem I have with this is I have been told I have to do this on my time. Had i been out on workers comp i would understand having to go where and when they say. However, I am spending upwards of three hours on my days off with no other compensation than mileage. Is this legal for me to have to continue making these trips on my time?