Major League Baseball won't implement an automated ball-strike system for home plate umpires by the 2025 season, according to commissioner Rob Manfred.

So-called "robot umpires" were among several topics addressed by the MLB commissioner during a news conference following an owners meeting on Thursday, the Associated Press reported.

As Manfred explained, the automated ball-strike system (ABS) hasn't developed as MLB would prefer since using the system in the minor leagues since 2019.

"We still have some technical issues," said Manfred. "We haven’t made as much progress in the minor leagues this year as we sort of hoped at this point. I think it’s becoming more and more likely that this will not be a go for ’25."

Manfred went on to explain that there's growing sentiment among MLB players that the automated ball and strike calls should first be implemented through a challenge system, which would still require umpires to rule on calls behind the plate and continue to reward catchers who are good at pitch framing.

"You could hypothesize a world where instead of a framing catcher who’s focused on defense, the catching position becomes a more offensive player," said Manfred. "That alters people’s careers. Those are real, legitimate concerns that we need to think all the way through before we jump off that bridge."

A challenge would likely be issued by a batter signaling to the home plate umpire that he wants the call reviewed, as demonstrated in this video (via CBS Sports' Dayn Perry):

One of the "technical issues" that MLB and the players association are trying to work out is the shape of the automated strike zone. Apparently, neither side wants the zone to be called as the rulebook states, which is the shape of a cube measuring roughly from the batter's armpits to his knees.

Currently, the ABS makes calls based on where the ball crosses at the midpoint of home plate, 8 1/2 inches from the front and back of the base.

"Originally, we thought everybody was going to be wholeheartedly in favor of the idea if you can get it right every single time, that’s a great idea," Manfred added. "One thing we’ve learned in these meetings is the players feel there could be other effects on the game that would be negative if you use it full-blown.