What do I do about my army reservist employee?

The problem A staff member has just told us that he’s joined the Territorial Army (TA). While we admire the armed forces and would like to support him, we are only a small company and are worried about the implications for the business.We don’t operate with spare capacity, so what will happen if he is called away for training or sent to Afghanistan?How can we manage this individual fairly while ensuring that our business needs are met?