Widebody Transport
Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness
ATC Issue All Types
Flight Crew Became Reoriented
Procedure
While performing a last minute runway change; out of the blocks; resolving a discontinuity; I saw a potential source for a routing error. Two of the waypoints are spelled very similarly. They are: PRYMD; which is part of the DUCKS 4RNAV SID; and the other waypoint is PYRMD; which [is] an enroute waypoint used in our departure clearance. These two waypoints are somewhat close to each other; when resolving a discontinuity on the FMS. We brought up this in our HF (human factors) briefing; and my crew agreed with reporting this potential departure/routing conflict to light. The cause of this event is difficult to pinpoint; since the pronunciation and spelling are different for those two waypoints. This oversight was caught by following company procedures which calls for slowing down when faced by a disruption; and pay attention to details. Enroute ATC planners were not aware of the waypoint similarities to the MEM SID waypoint in question; ie. PYRMD vs PRYMD.Immediately rename one of the two waypoints in question. In the future; more coordination between authorities to avoid future conflicts; especially during these new times of more FMS direct routing clearance procedures.
Air carrier Captain reported noticing a potential for a navigation error involving two fixes with similar spelling - PRYMD and PYRMD - while preparing for departure from MEM.