Tommy John Surgery... the three words every baseball pitcher dreads hearing.
It indicates a long tedious road of rehabilitation and valuable time away from the game. The rehabilitation following surgery generally takes 12 months to return to pitching and 18 for a full recovery. There are also usually 2-3 months prior to surgery where most pitchers follow conservative care attempting to avoid surgery. All told, it may be 2 years from initial injury until you are pitching 'normally' again.