As “Breaking Bad” prequel “Better Call Saul” heads into its fourth season, the series is experiencing new challenges — specifically through exploring Saul (Bob Odenkirk) as Jimmy McGill in the past and Gene, a Cinnabon manager in his post-“Bad” future, and without Chuck (Michael McKean).

“The only person on Earth left for Jimmy to care about and for the love and respect to earn is Kim,” Odenkirk said of his relationship with Rhea Seehorn’s character at the ATX Televison Festival Saturday.

While there was a tease that Chuck could make an appearance at some point in the season, Odenkirk pointed out the focus for him were two pivotal scenes between Jimmy and Kim that “include an element of forgiveness and reaching out and becoming a slightly better person than they are.”

“You’re going to wish they work it out,” he said.

However, her absence in the “Breaking Bad” world “makes it all the more tragic,” he continued. “You see these moments where they have what it takes.”

Executive producer Vince Gilligan, who stepped away from day-to-day work on “Better Call Saul” (he directed an hour in the upcoming season), admitted Gene holds the most interest for him at this point.

“There is the possibility for redemption with Gene,” he said. “The whole thing could end sadly instead of happily. But to me, that’s one of the more potentially hopeful things.”

While Jimmy’s inevitable decline into the Saul Goodman plays out, Odenkirk allowed that the transition has been difficult.

“My problem this year is I found a desire to change this journey a little. It’s sad to me,” he said. “I’m starting to feel bad he’s going to be this guy who has abandoned any idealism he had, and the hope of being a good person, which he has had. And he’s just starting to go, ‘F—k that s—t. No one is going to give me a chance? I’m just going to throw bombs around.’ That makes me sad.”

It’s certainly a darker spiral for the character whose origin story was originally floated as a joke.

Odenkirk recalled that as he and Bryan Cranston filmed their characters’ first meeting in the 2009 episode of “Breaking Bad” entitled “Better Call Saul,” “somebody said, ‘Can I get a job on the sequel?'” The notion remained in conversation, though almost always in jest — until ultimately, “Breaking Bad” creator Gilligan and co-executive producer Peter Gould sold the prequel — without a solid series plan in place.

“One of our first thoughts was maybe it would be a half-hour single-cam,” Gilligan said. “[Or] ripping off ‘Dr. Katz.’”

Though “Breaking Bad” was a critical and award season success, Gilligan strove to continue the universe to avoid a creative block. He worried if he took a long enough break, he’d “seize up.” Instead, the team finished post-production on “Breaking Bad’s” final season on a Friday and opened the “Better Call Saul” writers’ room on a Monday.

“That was healthy,” Gilligan said. “I feel silly saying this, because I could not be more proud of ‘Better Call Saul’ now. We took it seriously, but if I had known how good it was going to be…it was good to not take it too seriously, because that way leads to creative paralysis.”

Now with the success of “Better Call Saul,” too, Gilligan isn’t entirely shutting the door on expanding the “Breaking Bad” world further. When asked whether there was the potential to spinoff Kim to explain where she was during the “Breaking Bad” timeline, he expressed interest.

“That would be a great spinoff,” he said. “[But] at a certain point, I don’t know…how many spinoffs does the universe support before it collapses?”