Al Jean tells THR that he's not sure why Shearer is ready to walk away from what could be a four-year deal to remain on the series.

Should Harry Shearer turn his back on The Simpsons, the voice actor would be walking away from a potential four-year deal for the Fox animated series — and showrunner Al Jean isn't quite sure why the Emmy winner is unhappy.

Shearer, who voices iconic Simpsons characters including Mr. Burns, Ned Flanders, Principal Skinner and Kent Brockman, announced late Wednesday that he was planning to leave TV's longest-running comedy over a contract dispute and, as he phrased it, the "freedom to do other work."

This isn't the first time that the actor and comedian — who has been with The Simpsons since its origins on The Tracey Ullman Show — has had a contract squabble with the series. He was the lone cast holdout in the latest round of negotiations. The actors agreed to a pay cut in 2011 after fierce negotiations, and they stopped going to script readings in 2004 before eventually landing pay bumps.

In a frank interview with The Hollywood Reporter, Jean explains that he's not entirely sure what Shearer is unhappy with, as the five other voice stars signed their deals for the newly renewed seasons 27 and 28 of the Fox family comedy on May 1.

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The Simpsons was renewed for two more seasons — and now Harry claims to be done from the series. What happened here?

I'm a little baffled. The other five [voice stars] signed on May 1 and we offered him the same contract everybody else got offered, but he didn't sign so we started reading like we were going to and [were] waiting to see if he wanted to come back or not. Then about a week ago TMZ somehow got ahold of a story that [an unnamed voice actor from the cast] wasn't returning. Then last night Harry tweeted something to the extent that he was leaving the show — implying he wasn't wanted — which isn't true. We made him an offer and we're once more saying, "Do you want to come back like everybody else and work hard and care about the show? Great." He said he wanted to do other projects, which makes no sense because we've always let the cast do all the other projects they want — they have great free time. So I don't really know what he's up to [or] what he's thinking. I hope he comes back. The other misinformation that has been spread is that it would jeopardize these two seasons we're doing up until 625 episodes. That's for sure a pickup from the network, and everybody else is pay-or-play — so we'll make those episodes. If he chooses not to come back, we'll recast. We will not kill his characters; that's one way to go. I'm sure there will be plusses and minuses with that and, at the moment, I'm hoping he comes back. But if he doesn't in a reasonable time, we'll have to do the other options.

What's the reasonable time?

It's a little vague because we have seven holdover [episodes already completed]. The new episodes featuring his characters that haven't been recorded by him don't air until November. So I would say we have the summer to figure it out. But you want to know. It's not a hard decision. You should know the money is not going to change; it's not going to be different from what the other cast members get. They're saying the terms are the same, so I think Harry knows if he wants to do it or he doesn't want to do it. I hope he does.

In terms of the salary, there's a CNN report circulating that he's walking away from $14 million.

That sounds right. It's a two-year guarantee — the same rate as the other cast: all shows produced. Which should be 44 times whatever the show [per episode] fee is.

Harry has feuded with the show in the past. Do you have any backups in place for all of his characters?

Seeing how we have always hoped he'd come back, no we don't have anybody where we go, "Oh, that's the new Burns, that's the new Flanders" or anything. There are so many talented voiceover actors that come to mind immediately. Somebody like Billy West or Maurice LaMarche (Futurama) or Tom Kenny (SpongeBob SquarePants). I'm sure since he leaked the story, we've already been contacted by really good people — really funny people who can do voices — so I'm sure we'll have a lot to look at. The show will go on, and I think it will be a great show one way or the other.

If the voice cast have the freedom to do other projects outside of The Simpsons, what's Harry upset about?

He lives in England. He does a radio show and a play about Nixon. I'm not trying to be argumentative but I have no idea what we're preventing him from doing. The time commitment for him is: there are 22 reads, which you can do via phone. One hour per phone. He can record via phone, doing more than one episode at once, and pick those up within an hour or two. So, if you do that math, I don't know. This is why I'm really baffled. He's saying it's not the money, and it can't be money because there's not going to be a different offer he's going to get. TMZ, [where] to be accurate, he wasn't being quoted — I don't know if it came from a representative of his or some other source — said something about a backend [of the profits], but that's not it. It can't be the availability to do other projects, and it isn't that the deal is different than his other cast members. I don't know. Honestly, if it was me, I would take the deal right now. I wouldn't be waiting one second. I'm not trying to be disingenuous — I wish him well — but I don't understand. I'm perplexed. I understand if, for example, somebody like [The Sopranos'] James Gandolfini said that this is such a stressful job; I'm working on a six-hour, six days a week, and I'm playing this horrible man and I'm exhausted. I understand that kind of person saying the job prevents them from other things, but I don't understand it in voiceover.

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The Simpsons producers are said to have the right of refusal on specific projects for the cast. Is that part of all of deals?

Not to my knowledge. We wouldn't want somebody doing the voice of one of our well-known characters on something else. We're protective of that, but if Harry wanted to do an animated feature where he wasn't using his Simpsons voices, my understanding is we'd say great, go ahead. Hank Azaria did do another animated feature, Anastasia, for Fox. Nancy Cartwright has done a great deal of animated work in television. Harry appeared in the movie Godzilla and his own movie Teddy Bear's Picnic. He's made documentaries. I guess what I'm saying is, I think this is a false [reason]. I wish somebody would ask him what he's talking about because I have no clue.

At this point, what's different about this negotiation than in years' past? It sounds like these deals don't really change too much.

No. A few years ago [producers] said — like they do to a lot of shows, not just the Simpsons — that the budget was high and revenues were down, which is true. So we cut the budget and that was different but other than that it's same. But the difference here is that we've always had a deadline, and then they've signed and gone on, and now we have one person who didn't sign but wants to say we fired him, I guess, but doesn't want to just pick up the phone and say I want the job.

At this point if he did pick up the phone and say he wants the job — but also wants X, Y and Z, does he have any wiggle room at this point?

But I don't know what X, Y and Z are, that's what I'm trying to say. If he said, "I want freedom to do stuff," he has it. If he wants a deal different than the cast, he can't get it. I don't know what else you could want with this job. It's pretty simple. If you really didn't want to do it then, yeah. I really don't understand it. There's nothing. There were a couple issues that we said, "You know what, let's not make a deal of it." We listed the issues. It's the same deal the other guys got. He can take it if he wants it. I mean, it's not open-ended forever.

If Harry is reading this, is there something you would like to say specifically to him?

Please call [executive producer] Jim Brooks and tell him what you want. And if you don't want to do this show, tell him, but explain what's on your mind. Will the show go on without him? It will.

If this is truly the way things end with Harry and The Simpsons, it’s a sad culmination to such a long relationship. Would you feel badly about it?

Life is so full … I was divorced and things don't always end the way you hope, but I feel we've done everything we can to keep him on this show. We have made it a terrific job that's really well paying. He's won an Emmy for it. He has gotten acclaim worldwide. He can live in another country. He can phone it in and do whatever else he wants. So I don't know what else. I kind of defy you to find a problem.

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If this is his end with the series, which of his characters do you think would be the hardest to replace?

I don't even want to talk about that yet because that's at least an issue for next week, if not later. It'll be done. It's a different issue, [but] when Marcia Wallace died, we didn't bring her character back. But I can't feel like we should end the show where all these people work, all these animators, people who aren't necessarily in the public but have worked here for a long time, because one person doesn't want to accept a deal of that magnitude. I don't think it's right to end it. So I hope he takes it, but it wouldn't end it because he didn't I don't think that's a good reason.

Should this be the end of the line for Harry's tenure with this show, how do you see replacing his voice roles? You've gotten a lot of offers, but is the plan to keep all of his iconic characters?

Pretty much. We really don't know. I don't think one person would do exactly all of them. We'd see who could do what and we'd also have people who could not just do the characters but maybe do other funny things, too. But I think it would be a really wide open world because it's a great show and there's a lot of work for somebody who's good.

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If you wind up replacing some of his characters — like Flanders and Mr. Burns — do you think viewers would be distracted by the new voices?

Of course it's a concern. People doubted when we went from ink-and-paint to digital to high-def. However you change in life, people fight at first. But no, I think they'd be fine. You know, there's a Simpsons ride at Universal Studios that Harry didn't do. He's not in it. He didn't want the deal that everybody else took. And people love it — and I've never heard anybody say they miss him. Similarly, it was a good deal that everybody else took and he didn't.

Why didn't he want to take it? Did he explain?

Part of the same mystery.

Do you think this opens the door for other cast? I know that they've signed for two more seasons but given the show's track record do you think that there's concern?

It's a really different issue. They are signed for a four-year contract [with] two-year options on Fox.

So at this point Fox has options for seasons 29 and 30?

Yes. Not only that but Harry would ostensibly lose that money if he turned this down. I want to stress that we'd really like him to come back. We're not forcing him out. I'm genuinely confused by what he's saying, and I hope he calls Jim.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit