ARLINGTON, Texas -- Major League Baseball hopes to test robot umpires as part of a challenge system during spring training next year, making an automated ball-strike component possible as early as 2026. But MLB commissioner Rob Manfred still seems far from committing to that date, saying Tuesday that the league has "technical issues surrounding the definition of the strike zone" that need to be ironed out before it is even tested by major league players.

"We need '25 to do the spring training test if we can get these issues resolved, which will make '26 a viable possibility," Manfred said during his annual pre-All-Star Game gathering with the Baseball Writers' Association of America (BBWAA). "Is that going to be the year? I'm not going to be flat-footed on that issue."

MLB has been experimenting with an automated ball-strike system, or ABS, at the minor league level for the past five years and began using it at all Triple-A ballparks in 2023. Initially, half the games used ABS for every call and the other half used the challenge system, but MLB went exclusively to a challenge system -- wherein the plate umpire calls balls and strikes as usual and teams have a limited number of calls that can be reviewed -- on June 25.

The switch, Manfred said, was "almost 100 percent" based on feedback from players, who prefer a challenge system over full ABS. Manfred added that the accuracy of ABS is "good to a hundredth of an inch" and the technology on the path of the ball is "perfect" -- but that it's still not fully ready.

"One thing we learned with the changes last year is -- a little more time is better than not enough time," Manfred said. "And I mean that just in terms of making sure -- when you bring something to the big leagues, you got to make sure you've got it right."

Rule changes go before an 11-member competition committee that consists of an umpire, four players and six team representatives, giving MLB the most votes when it comes to implementing new rules -- which it used to incorporate a pitch clock, bigger bases and restrictions on infield shifts before the 2023 season. Players have previously expressed frustration that their input on new rules hasn't been fully heard, particularly as it pertains to further limits on the pitch clock in 2024.

Another wrinkle is the expiration of the umpires' collective bargaining agreement at the end of the 2024 season, with MLB's desire for ABS expected to be a major part of the negotiations. Tony Clark, executive director of the MLB Players Association, called player input on ABS "interesting."

"There are those that have no interest in it at all; there are those that have concerns even with the challenge system as to how the strike zone itself is going to be considered, what that looks like, how consistent it is going to be, what happens in a world where Wi-Fi goes down in a ballpark or the tech acts up on any given night," Clark said in an earlier session with the BBWAA. "We're seeing those issues, albeit in minor league ballparks. We do not want to end up in a world where in a major league ballpark we end up with more questions than answers as to the integrity of that night's game, or the calls associated with it."