The short answer: Yes, you can. The longer, better answer: Don’t do it and here’s why …
“He who represents himself has a fool for a client” is a quote often attributed to Abraham Lincoln but the true origins of the proverb are unknown. An early example appears in 1814 in The Flowers of Wits by Henry Kett, wherein the eminent lawyer states, “I hesitate not to pronounce, that every man who is his own lawyer, has a fool for a client.”
Workers’ compensation law is complicated. Even if you have been handling your case without difficulty to this point, there will, almost certainly, come a time when a conflict with the insurance company will arise. Your odds of successfully resolving that conflict favorably on your own are almost zero. This is especially true if you are required to go to a hearing to resolve the issue as the rules of evidence are also complicated.
Don’t try to represent yourself. You will be shortchanging your foolish client.