The invention is directed to manipulator assembly (2) for holding and manipulating a surgical instrument (14) in a telerobotic system. The manipulator assembly includes an instrument holder removably coupled to a drive assembly so that the holder can be sterilized. The assembly further includes a force sensing element (52) mounted distal to the holder and the drive assembly for detecting forces exerted on the surgical instrument and providing feedback to the surgeon. The invention is also directed to a system and method for releasably holding a surgical instrument (14). The system includes an instrument support for automatically locking mounting pins on the instrument within locking slots on the instrument holder to releasably couple the instrument to the holder. With a twist-lock motion, the surgeon can rapidly engage and disengage various instruments from the holder during a surgical procedure, such as open surgery, laparoscopy or thoracoscopy.