We have less than 20 employees. Customers and morale are suffering considerably because our employees are having to cover a full time position during the absence. Employee has been out for over 1 month, and an anticipated return no earlier than another 1-2 more months. Employee has been given repeated job performance warnings, as early as just prior to the disability. Employee is hourly and signed a Handbook that clearly outlines "at will" employment. Can we terminate the employee for poor job performance during their disability leave and hire a replacement, while still maintaining compliance with the FMLA and any applicable California laws? Thank you.