"I think he would go looking to prove that, either one way or the other," James said at San Diego Comic-Con when asked how Morgan would react if he knew Rick was gone-slash-missing.
"I think he would walk back across the country, I think he'd walk back and forward. It would become his new mission. He would have to find him."
For Morgan, who was first to form a bond with Rick in the wake of the apocalypse, "He still defines himself by that man, and that friendship, and the fact that those two men know each other in a way that they don't allow anybody else to know them," James said.
"So it would be very fundamental to him."
When asked by TV Guide if Morgan and Rick could potentially reunite in the coming trilogy of Walking Dead films, to be released in theaters via distributor Universal Pictures, James said he would "absolutely jump" at the chance.
"I had a great time working with Andy," James said. "I'd work with him any day of the week. So any opportunity to be back in front of the camera, hanging out on set with him, I would absolutely jump at."
Lincoln is similarly optimistic Rick and Morgan's goodbye at the junkyard once overseen by Anne (Pollyanna McIntosh) would not be their last meeting.
"There was a sort of sense, certainly, with Lennie, that it's until we meet again. It's always been that way with Rick and Morgan," Lincoln previously told EW when James exited TWD to join its spinoff.
"I don't know, there's something in the air, that I feel that it's not quite the end yet for Rick and Morgan."0comments
When Lincoln opened up about the departure to ComicBook.com, he noted the two men "have an intense habit of finding each other, no matter what channel they're on."
Fear the Walking Dead Season 5 resumes Sunday, August 11 on AMC.