NEW YORK -- Robot umpires will get some more warm-up time.

Major League Baseball and the Atlantic League said Wednesday the experiment with radar-tracking technology to call balls and strikes will not be used when the independent minor league starts play on April 25. Instead, the technology "will be implemented gradually over the course of the 2019 season." No date for the start was announced.

Plate umpires will wear earpieces and be informed of ball and strike calls by a TrackMan computer system that uses Doppler radar. Umps will have the ability to override the computer, which considers a pitch a strike when the ball bounces and then crosses the zone. TrackMan also does not evaluate check swings.

A second test also was pushed back: extending the distance between the pitching rubber and home plate by 2 feet to 62½ feet. Originally scheduled to start after this year's All-Star break, the distance change was put off until the second half of 2020.

"These changes reflect a joint desire that the upcoming technology upgrades at ALPB ballparks be fully installed and calibrated prior to implementation of these experimental playing rules," MLB and the Atlanta League said in a joint statement.

Atlantic League teams are in Bridgewater, New Jersey; Central Islip, New York; High Point, North Carolina; Lancaster, Pennsylvania; New Britain, Connecticut; Sugar Land, Texas; Waldorf, Maryland; and York, Pennsylvania.