Sheen 'Shocked' by Lowe's 'West Wing' Departure

July 25 -- Rob Lowe won't be leaving The West Wing until midway next season … but he is definitely leaving.

Even Martin Sheen, who plays President Josiah Bartlet on the White House drama, is "shocked and dismayed" by the news.

"We're all heartbroken and a bit concerned because we'd become so close, Rob and me, in particular," Sheen said.

"I've known him since he was a boy. He grew up with my family and I've been kind of a Dutch uncle to him all these years, and to have the last three years together like this, we've gotten extremely close." Lowe Reportedly Denied Pay RaiseLowe's salary is at the heart of the dispute. He has reportedly been earning the same $75,000-an-episode paycheck since the series began in 1999 and he's upset the show's producer, Warner Brothers, wouldn't even consider giving him a raise, even though other cast members have received salary increases.

Sheen's salary recently tripled, reaching $300,000 an episode. Cast members Bradley Whitford, Richard Schiff, John Spencer and Allison Janney joined forces to successfully pressure producers for pay hikes, although they reportedly still make less than Lowe.

"We knew that there were some contract disputes, but I never get into that with another fellow actor because, frankly, it's none of my business," Sheen said. "Everyone's entitled to go for whatever they can get. I did, certainly."

Last year, Lowe was nominated for an Emmy and two Golden Globes for his role as White House Communications Director Sam Seaborn, although he's virtually the only cast member who didn't get an Emmy nod this year.

"As much as it hurts to admit it, it has been increasingly clear, for a while, that there was no longer a place for Sam Seaborn on The West Wing," Lowe said. Sam Sticks Around for 16 EpisodesThe plan now is for Seaborn to be written out of the show in March, to give the show a graceful transition. "Rob has been a huge and great part of the program," said NBC Entertainment President Jeff Zucker.

"We're fortunate that he's going to be with us for virtually the entire year and after that, Sam Seaborn will move on to other things."