MIAMI -- Union head Tony Clark claims Major League Baseball's rules changes would have gone more smoothly during spring training if player thoughts had been incorporated.

Clark added that the changes could have a different effect on the games once the regular season begins and the "lights come on."

MLB implemented its first pitch clock, limited defensive shifts and pickoff attempts and installed larger bases as part of the biggest alteration in playing rules since the mound was lowered for the 1969 season.

"My hope despite the fact that nearly all of the things that we have seen that would otherwise be characterized as challenges could have been avoided with the input that the players offered when these rules were being constructed," Clark said Saturday before the United States played Venezuela in the World Baseball Classic quarterfinals.

"My hope is that moving forward that the league continues to take the input of players to heart, such that each of the adjustments that we've seen that have been implemented this year are of benefit in the long run."

The average time of spring training games has dropped to 2 hours, 36 minutes, from 3:00 last year. The changes have had almost no impact on offense, with runs per game rising to 10.7 from 10.6 and batting average to .260 from .259.

Stolen bases have gone up to 1.8 per game from 1.1.

"Spring training is spring training," Clark said. "I appreciate everyone focusing on spring training game times have been shortened by `X' number of minutes. I appreciate everyone's focus on it. But when the lights come on and these count, count for the managers, count for the organizations, count for the players, we'll see how all of these moving pieces come together."

After the Mets' Max Scherzer timed the pitch clock to throw a quick pitch to Washington's Riley Adams on March 3, MLB reminded teams that a pitcher must wait until a hitter is reasonably set in the batter's box to deliver a pitch.

Baseball's 11-man competition committee, established in the labor agreement last March, adopted the pitch clock and shift limits last September over the opposition of the four players on the panel.

Saying it was responding to player concerns, MLB set the pitch clock at 15 seconds with no runners and 20 seconds with runners, up from 14/19 at Triple-A and 14/18 in the rest of the minors.

MLB also liberalized its planned limit for pickoff attempts, known as disengagements. In the minors, a pitcher had two pickoff attempts per plate appearance and a third would result in a balk unless there was an out. In the majors the limit resets if a runner advances.

MLB umpires also have permission to provide additional time if warranted, such as the catcher making the final out of a half-inning. MLB altered limits on mound visits, which started in 2018, adding an allowed trip in the ninth inning if a team has exhausted its total by the end of the eighth.

This is the fifth edition of the World Baseball Classic, started in 2006, and the first since 2017 following a delay caused by the coronavirus pandemic. There seems to be little support for holding WBCs more frequently.

"Having it happen as perhaps infrequently as we do offers a certain level of excitement around the event akin to what you often see with the Olympics every four years, as well," Clark said.

He was not concerned that the U.S. team has been given more limits on pitcher use than other nations.

"Each federation and each country against the backdrop of when their season starts and how that federation works have their applicable guidelines for participation for their players," he said. "Ours may be a little different than some others."

Clark also said it was feasible to reach an agreement on a collective bargaining agreement for minor leaguers by opening day on March 31.

"A lot of progress has been made," he said. "We'll see if we're able to get it across the finish line before opening day."