Cardiff lock Teddy Williams is one of the major autumn absentees after dislocating his foot against Connacht, an injury which could see him miss the rest of the season.
Fellow Cardiff players James Botham and Mason Grady are also sidelined because of injuries.
Scarlets captain Josh Macleod and Exeter flanker Christ Tshiunza will definitely miss the November matches because of injuries, while hooker Ryan Elias and centre Eddie James are expected to miss most of next month’s action.
In addition to the fitness issues for Morgan and Rees-Zammit, Tandy also has a series of other niggling injury concerns.
Dragons hooker Elliot Dee has not featured so far this season while Ospreys duo Giles and Keiran Williams, who have both enjoyed promising starts to the season, were late withdrawals before the 42-17 defeat against Glasgow in Bridgend.
Ospreys scrum-half Kieran Hardy was already ruled out of that game after coming off against Zebre with a rib injury.
Prop Rhys Carre is fit and has started the season strongly with Saracens – but is currently ineligible under the WRU selection policy because he has 20 caps, five short of the required number for those playing for clubs outside Wales.
So a rule change or loophole from Wales would be required to see his return.
Carre will become available for the other home nations in 2026 because it will have been three years since he previously played for Wales.
