Section 39A. No professional boxer, licensed under section thirty-five, who has been knocked out, technically or otherwise, six or more times in the preceding twelve months, shall take part in a boxing or sparring match or exhibition until he has been examined and found fit to take part in such a match or exhibition, by a physician selected by the commission, at a place and time designated by the commission. If any such boxer is found unfit to engage in any such boxing or sparring match or exhibition, he shall be excluded from such participation in this commonwealth for a period of three months, after which time he may make a request to the commission for another physical examination.