You don't want to risk generating undue concern, or distract from the work. When pain is increased by work and carries over each day, or if it's waking someone up at night, early response pays off for everyone in the long run. When someone reaches a stage where they have an injury that requires treatment, your support can help them recover more effectively and get back on the job. That in the end is what everybody wants - you and the worker. During the recovery process, any additional stress carried by the individual is only going to serve to slow the recovery process.
Stress interferes with the physiological processes involved in healing.
Often, someone usually needs to go to therapy, possibly twice or more per week. Most people try to do this early in the morning, during lunch, or at the end of the day to have the least impact on their jobs, and try to be especially productive to make up for it. They need to feel free of pressure that their need to be away from the office is not viewed unfavorably. If someone has to take a period of disability off, then it's important that you stay in touch, that you call once in a while to see how they are. We are, after all, human, and work relationships are still connections between people who want to feel valued and cared for.