A lock assembly for use in conjunction with a trocar sleeve includes a lock assembly housing having an aperture extending therethrough. The lock assembly also includes a cam lever and an elastomeric block positioned within the lock assembly housing. The cam lever includes a first end pivotally secured to the lock assembly housing and a free second end that is adapted for user actuation, wherein rotation of the cam lever brings the elastomeric block into engagement with an instrument passing through the lock assembly housing for locking an instrument relative thereto.