MLB Commissioner Rob Manfred announced changes intended to speed up pace of play. (Charles Rex Arbogast/AP)

MESA, Ariz. — Determined to speed up baseball’s pace of play but unwilling to inflame the union at a time when labor relations are already tense, baseball Commissioner Rob Manfred on Monday announced a set of initiatives for 2018 that includes a limit on mound visits and reduced commercial breaks between innings — but no pitch-clock.

“I am pleased that we were able to reach an understanding with the Players Association to take concrete steps to address pace of play with the cooperation of the players,” Manfred said in a statement Monday. “My strong preference is to continue to have ongoing dialogue with players on this topic to find mutually acceptable solutions.”

The new rules were negotiated with the union, which refused to agree to them but signed an agreement saying it would not oppose them. Manfred’s statement made clear he reserves the right to implement the pitch-clock in future seasons — with ball-strike penalties — if this year’s changes don’t improve the pace of play.

Manfred, according to the release, “has decided to defer the implementation of a pitch timer and a between-batter timer in order to provide players with an opportunity to speed up the game without the use of those timers.”

In his own statement, union chief Tony Clark said, “Players … are committed to playing a crisp and exciting brand of baseball for the fans, but they remain concerned about rule changes that could alter the outcome of games and fabric of the game itself — now or in the future.”

Beginning this season, teams will be limited to six non-pitching-change mound visits per nine-inning game, with one additional visit permitted in each extra inning. A mound visit is defined as a manager or coach visiting the mound, a player (including the catcher) leaving his position to confer with the pitcher, or the pitcher leaving the mound to confer with another player. The umpire can grant additional visits under defined circumstances, such as injury, the announcement of a pinch hitter or confusion between the pitcher and catcher over signs.

In addition, commercial breaks between innings and during pitching changes will be reduced to 2 minutes 5 seconds for most regular-season games, 2:25 for nationally televised regular season games and 2:55 for postseason games.

“I think MLB is doing a good job of trying to speed up the game a little bit,” Washington Nationals Manager Dave Martinez said. “We’re all trying to work together to create good ideas. The games do tend to get long sometimes …. But I know they’re working diligently to get it right.”

Manfred first raised the idea of a pitch-clock to speed up the game a year ago, but it was met almost immediately with resistance from the players. After the league average time-of-game crept up to 3 hours 5 minutes in 2017, an all-time high, Manfred pressed the union again to agree to changes for 2018.

But with management and the union at odds over the state of this winter’s free agent market — with many seemingly desirable players still unsigned with spring training camps now open across Florida and Arizona — Manfred may have wanted to avoid an additional confrontation over pitch-clocks, knowing the players’ opposition to them.

Jorge Castillo contributed to this report from West Palm Beach, Fla.

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