Routis has been hampered with a calf problem recently, while Morris still cannot quite shake off the affects of a troublesome knee injury that has been an issue for the midfielder since the middle of September.
Parkinson expects Routis to return to training next week but Morris will have to be monitored after receiving further treatment on his own injury problem.
With Lee Evans suspended for Sunday's tie, Reece Burke could join him on the sidelines following a slight injury to a hip flexor muscle during Tuesday's win over Blackpool.
Fellow centre half Nathan Clarke is in line to step in if Burke isn't passed fit for the match at Aldershot's EBB Stadium.
Parkinson said: "We're expecting Chris to be training on Monday.
"With Josh, he's had another injection in his knee. We are going to have to be patient with him over the next ten days."