No one knows for sure if NCIS supervisor Jethro Gibbs survived the attack in Afghanistan in the season finale of "NCIS" season 12, even actor Mark Harmon. 

The actor, who portrays the role of the lead agent of the Naval Criminal Investigative Service team, appeared in "The Late Late Show with James Corden" in May, and he discussed the possible fate of Agent Gibbs. He said any cast member of the show is "replaceable," including him. 

"This show births characters leaving, it always has," Harmon told the late night show host. "I think it keeps actors healthy. It's not my choice, number one, but I think anyone is replaceable." 

Corden implied that the staff of "NCIS" will not dare to fire Harmon from the show, but the actor just told him that it is not impossible. 

Speculations about Harmon's exit from the long-running crime procedural drama surfaced when Agent Gibbs was fatally shot by young boy named Luke Harris. Luke put a bullet through his chest for a terrorist group named the Calling when he, Tony DiNozzo (Michael Weatherly), and Joanna Teague (Mimi Rogers) flew to Afghanistan to investigate the killing of Agent Dormeget (Matt Jones). 

Meanwhile, VC Post posted an interview with "NCIS" creator Gary Glasberg, saying that the upcoming season will start exactly where season 12 left off. According to Glasberg, DiNozzo will take over Gibbs task to capture the members of the Calling. 

In FOX News, the series creator shared his plans for "NCIS" season 13, saying, "As I have done historically, I will probably get into six or seven episodes of more traditional storytelling and into the background of our characters and whatnot, and then figure out what's next and launch something significant," the series creator shared. 

Does this mean that Gibbs will be taken out of the picture? 

"NCIS" season 13 is slated to air later this year.