An instrument chassis for a robotic surgical system comprises a bridge member, a first instrument guide member configured to receive a first surgical instrument, and a second instrument guide member configured to receive a second surgical instrument. Each of the first instrument guide member and the second instrument guide member is moveably coupled to the bridge member such that each of the first instrument guide member and the second instrument guide member is moveable in at least one degree of freedom relative to the bridge member. The instrument chassis further comprises a central instrument guide member coupled to the bridge member between the first instrument guide member and the second instrument guide member. The central instrument guide member is configured to receive a third surgical instrument. Each of the first instrument guide member and the second instrument guide member is slidably movable relative to the bridge member.