When Bobbi "Mockingbird" Morse and Lance Hunter left "Agents of S.H.I.E.L.D.", they did so with the promise of a spin-off series. However, since "Marvel's Most Wanted" wasn't picked up by ABC, fans have been clamoring for the two fan-favorite agents to return to the show they originated on. According to executive producers Maurissa Tancharoen and Jed Whedon, that won't happen anytime soon.

“One can only dream,” Tancharoen told Entertainment Weekly. “That’s always on our minds.”

“Once an agent, always an agent, so it’s always out there in the ether,” added Whedon. “But right now we’re taking a breather.”

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Mockingbird and Hunter -- who are played by Adrianne Palicki and Nick Blood, respectively -- last appeared in the "Agents of S.H.I.E.L.D." Season 3 episode "Parting Shot." There, the duo was sent to Russia, where they became entangled in an assassination plot. After they were caught spying on a Russian facility and killed several agents in the process, Coulson was forced to disavow them; ultimately, they were free to go, but they could never work for S.H.I.E.L.D. -- or any other government agency -- again.

The episode was intended to lead into the pilot for "Marvel's Most Wanted," which would have starred Palicki, Blood and Delroy Lindo as Marvel Comics’ swashbuckling spy Dominic Fortune. The two ex-agents would have been on the run, but working with Fortune as he tried to further his own mysterious agenda. Oded Fehr and Fernanda Andrade were also slated to star.

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"Marvel's Most Wanted" received a pilot order, but wasn't picked up to series. ABC announced that show wouldn't move forward last May. “Most Wanted, ultimately at the end of the day, did not feel as strong as some of the other pilots that we shot,” ABC Entertainment president Channing Dungey said at the time. “We talked about it with Marvel and we all came to an agreement that we want to figure out what the next show is that we do together, is something that we all feel is as creatively strong as it can be.”

As such, Palicki and Blood have not reprised their roles on "S.H.I.E.L.D." since "Marvel's Most Wanted" was terminated, and fans continue to ask when they will return. However, as evidenced by Tancharoen and Whedon's latest statements, that isn't in the cards right now. As it stands, Palicki and Blood have pursed other work since the news about "Marvel's Most Wanted" broke, so their absence could be chalked up to the actors' schedules, or the current story arc on "S.H.I.E.L.D." simply may not be able to accommodate the characters.

Airing Tuesdays at 10 pm ET/PT on ABC, “Marvel’s Agents of S.H.I.E.L.D.” stars Clark Gregg as Agent Phil Coulson, Chloe Bennet as Daisy “Quake” Johnson, Ming-Na Wen as Melinda May, Iain De Caestecker as Leo Fitz, Elizabeth Henstridge as Jemma Simmons, Henry Simmons as Alphonso “Mack” Mackenzie and more.