At Omaha, Henry coached many of the pitchers that currently make up the Royals' bullpen.
"I'm going to stay out of their way and watch 'em go, just like I did when I was in the Minor Leagues," Henry said. "There's not a lot to do, those kids are pretty good."
Henry will work closely with pitching coach Dave Eiland.
"It's his staff, I'm just there to help him out," Henry said. "It's going to be a good learning tool for me as far as where my career is going. I'm there to help out any way I can and every way I can, so I'm looking forward to it. When I was there for two weeks, he was real good to me, showing me what he needs and what he's going to want next year, so I've got a good rapport with him."
Current Royals starter Luis Mendoza often credits Henry for reviving his career at Omaha in 2010-11. Henry this year coached one of the Royals' hopefuls for the 2013 rotation, Jake Odorizzi.
"Odorizzi has a real good chance of making an impact," Henry said.
Still to be named for the 2013 staff is a hitting coach to replace Kevin Seitzer, dismissed after the season ended. In-house candidates include Minor League hitting coordinator Jack Maloof, Northwest Arkansas hitting coach Terry Bradshaw and Surprise hitting coach Andre David, who held the Major League job in 2005-06.
Henry, 48, pitched 11 years in the Majors with Milwaukee, the New York Mets, San Francisco, Houston and KC, compiling a 34-42 record with 82 saves and a 4.19 ERA in 582 games, all in relief.
Drafted out of Arizona State University by the Brewers in 1986, the 6-4 right-hander didn't make his big league debut until 1991 at the age of 27.
"It took me 5 1/2 years to get there, so it wasn't like it was a cakewalk for me," Henry said. "It helps me relate to these kids."
As a rookie in 1991, he had a career-best ERA of 1.00 and he had 29 saves the next year for the Brewers. For the Astros in 1998, he had an 8-2 record and reached the playoffs with them that year and in 1999. He was in the postseason with the Giants in 1997 and 2000.
In 2001, his final season of pitching, Henry was 2-2 for the Royals with a 6.07 ERA in 53 games.
"By far it wasn't my best year but I enjoyed it, and the people in Kansas City treated me very well even though I was having a bad year," he said. "There were no hard feelings when I left and I'm looking forward to coming back."
After retiring, he coached at the University of Wisconsin-Whitewater and later coached in the Atlanta Braves' organization. In 2008, he rejoined the Royals as the Class A Burlington, Iowa, pitching coach and, in 2009, he was a roving coach in the Minors.
"Doug has worked as a pitching coach or coordinator at nearly every Minor League level and brings a strong working relationship with a majority of our current Major League relief pitchers," Moore said. "His experience in the game will be invaluable to our coaching staff as well as the pitchers he'll interact with on a daily basis."