Commissioner Bud Selig opposes extending the division series from a best-of-five to a best-of seven.
"I think that exacerbates the problem," he said. "If you add two more in the first round, it just makes the playoffs longer."
Next year, Game 7 of the World Series wouldn't be until Nov. 5 under the current format.
"I've been worrying about that all day today," Selig said.
Selig admits the length of the postseason increases the likelihood of playing in cold weather.
"I won't do what Bowie used to do, though," he said, referring to former commissioner Bowie Kuhn. "I will not sit outside without a coat."
Speaking Saturday night, Selig repeated that he doesn't envision playing World Series games in the daytime anytime soon because the television networks aren't interested and ratings are lower. There hasn't been a World Series day game since 1987.