A Special Committee for On-Field Matters, appointed by Selig in December, suggested the change in which the day off between the fourth and fifth games of the best-of-seven LCS was removed.
A release from MLB said the change was "in response to concerns expressed by players and management" about the number of off days during the post-season.
"Scheduling is a key area in which the (committee) members have expressed many interesting ideas and opinions," Selig said. "The removal of the off-day during both League Championship Series marks the first step in a process that will ultimately result in an improved postseason format for our game."
Selig said he expected additional changes to stem from the committee's work.
The MLB post-season schedule for 2010 has three Division Series beginning Oct. 6, the American League Championship Series on Oct. 15 and the NLCS on Oct. 16. The World Series is to begin Oct. 27.