A robotic surgical system includes a surgical tool including a drive housing having first and second ends, a carriage movably mounted to the drive housing, and an elongate shaft extending from the carriage and penetrating the first end, the shaft having an end effector arranged at a distal end. An instrument driver is arranged at an end of a robotic arm and includes a body having proximal and distal ends and defining a central aperture extending between the proximal and distal ends, the shaft and the end effector penetrate the instrument driver by extending through the central aperture, an outer housing extending between the proximal and distal ends, a tool drive assembly provided at the proximal end and extending into the outer housing, and a drive motor operatively coupled to the tool drive assembly and operable to cause the tool drive assembly to rotate relative to the outer housing.