Childers was told after Saturday's race at Bristol that there would be a change with the No. 55 car, driven by Brian Vickers, so MWR could start preparing for next year.
Miller, the vice president of competition for MWR, will be the crew chief for the No. 55 for the remainder of the season, starting with Sunday's race at Atlanta Motor Speedway.
Vickers, who last week signed a new two-year deal with MWR, will be behind the wheel of the No. 55 for 11 of the final 12 races this season, while team owner Michael Waltrip will start at Talladega Motor Speedway.
Childers, who announced this past weekend at Bristol Motor Speedway that he was moving to Stewart-Haas Racing in 2014 to work with Kevin Harvick, will remain under contract with MWR until Dec. 31 and can't begin working early with SHR.
"Will just have to sit at home,'' Childers said.