Cashman said he had informed Eiland of the decision and said that it was not related to the pitching staff's struggles in the American League Championship Series against the Rangers.
"It has nothing to do with what took place in the playoffs; I just think as we move forward, we're going to make a change there," Cashman said. "He's not being blamed for what took place and how bad we pitched. I can honestly tell you that.
"I hope you believe me on that, but I can't control what you choose to believe. But that's the truth. As we move forward, we're making a change. I'm not going to go into any more detail on it other than what I just said."
Eiland, a one-time Yankees prospect who pitched in 36 games for New York from 1988-95, was hired to be a Minor League pitching coach and was promoted to the Major League club in 2008 with the arrival of manager Joe Girardi.
His relationships with the young pitchers like Phil Hughes and veterans like A.J. Burnett proved to be beneficial, as the Yankees ranked fourth in the AL with a 4.26 ERA in 2009, their lowest mark since 2002 (4.02), en route to their 27th World Series title.
"Dave spent his entire coaching career with the Yankees organization, and there is little doubt the impact he had on a great number of pitchers during his tenure," Girardi said in a statement released by the team. "He was a passionate and knowledgeable pitching coach on the Major League level, and he played a valuable role in our team's achievements in recent years. I wish him continued success moving forward as his baseball career continues to evolve."
Eiland's staff improved on its 2009 mark this season, registering a 4.02 ERA. Citing a "private family issue," Eiland took a leave of absence from the team from June 4-29.
Cashman said removing Eiland from the coaching staff was his decision.
"We're making a change as we move forward. It's as simple as that," Cashman said. "The reasons are personal. He's a terrific pitching coach, and he should have no problem getting a job. He knows what he's doing, but we move forward. We're making a change."
The Yankees have several internal candidates they could consider. Triple-A pitching coach Scott Aldred pitched nine Major League seasons from 1990-2000 and is well thought of, and organizational pitching guru Nardi Contreras could get a look. Bullpen coach Mike Harkey filled in during Eiland's absence in June.
When asked about possible replacements, Cashman said his first order of business is finalizing a new deal with Girardi, whose contract expires Sunday. Cashman said he plans to meet Tuesday with Girardi's representative, Steve Mandel.
"Obviously the first order of business is our manager. That should work out fine," Cashman said. "I know Joe wants to stay, and we would like to retain him, so that should create an environment we can work through rather quickly. After that, we'll focus on the entire coaching staff, especially that vacancy. It's an important one."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.