Can a post-injury waiver prevent our workers’ comp liability?

Q. Our safety officer insists that if workers have a minor injury on the job but refuse to seek treatment, they must sign a waiver. The waiver states that they refuse treatment and the company is no longer liable for their treatment. He says that we no longer have to submit a claim to workers' comp for that injury in the event that it becomes serious. (For example, a fall leaves a bruise but later the bone is found cracked.) What do you think? – Heather, Florida