Sealing assemblies and methods are disclosed for sealing a surgical instrument having an internal drive shaft subject to lateral displacement. A sealing assembly includes a rigid portion shaped to interface with an instrument shaft of the surgical instrument. A laterally oriented slot is open at a radially perimeter location and configured to receive an o-ring seal via the perimeter location. Apertures are disposed on opposing sides of the slot and open to the slot. The apertures are configured to receive the drive shaft there through and are larger than the drive shaft to accommodate lateral displacement of the drive shaft. The slot includes opposing internal sides spaced to interface with opposed axial surfaces of the o-ring seal. The seal inhibits axial transmission of an insufflated gas and/or bodily fluids while accommodating lateral displacement of the drive shaft.