If the employee recovers from disability and returns to work, then becomes disabled again and stops work, the employer shall pay any of the 45 days of entitlement to COP not used during the initial period of disability where:

(a) The employee completes Form CA-2a and elects to receive regular pay;

(b) OWCP did not deny the original claim for disability;

(c) The disability recurs and the employee stops work within 45 days of the time the employee first returned to work following the initial period of disability; and

(d) Pay has not been continued for the entire 45 days.