Runnells, the club's bench coach since May, 2009, is the first candidate to interview with senior vice president of Major League operations Bill Geivett. Club sources have said the process will start internally with Runnells and Triple-A Colorado Springs manager Stu Cole.
Several other names have emerged as possibilities, but the club has not gone far with any of them.
Runnells managed the Montreal Expos in 1991 and 1992 (68-81), and has worked in the Rockies organization since 2001.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.