A series of initiatives aimed at quickening the pace of play in Major League games was announced Friday.

The bullet points:

• Umpires will enforce Rule 6.02(d), which requires hitters to keep one foot in the box during an at-bat, subject to certain exceptions.

• Timers will be used to ensure that the game resumes promptly at the end of inning breaks.

• Managers will no longer come out of the dugout to initiate a replay challenge. A manager will also keep his challenge after each call that is overturned. Last year, a challenge was retained only after the first overturned call.

The changes were announced jointly by Commissioner Rob Manfred, Major League Baseball Players Association executive director Tony Clark and John Schuerholz, chairman of MLB's Pace of Game and Instant Replay Committees. The new initiatives will be in effect for Spring Training, the regular season and the postseason, and they will be reviewed after the 2015 World Series.

"These changes represent a step forward in our efforts to streamline the pace of play," Manfred said. "The most fundamental starting point for improving the pace of the average game involves getting into and out of breaks seamlessly. In addition, the batter's box rule will help speed up a basic action of the game."

Added Clark: "The Players believe that enforcing the rules that currently exist regarding between-inning breaks and plate appearances is the best way to address the issue of pace of play. We're confident that today's announcements will have a positive impact on the pace of the game without jeopardizing the integrity of the competition."

Donations will be made to the Major League Baseball Players Trust charitable foundation based on the level of adherence to the new rules.

Rule 6.02(d) was in place in the Minor Leagues last season and has been added for the Major Leagues this year. The exceptions that allow a hitter to leave the box include swinging at a pitch, being forced out of the box by a pitch, a time out or if the team in the field attempts a play on a runner at any base.

The umpire has the discretion to issue a warning instead of calling an automatic strike for a first offense if he deems it unintentional.

6.02(D), 2014 OFFICIAL BASEBALL RULES Rule was applicable in Minor League Baseball last year and will be used in MLB beginning this season. (1) The batter shall keep at least one foot in the batter's box throughout the batter's time at bat, unless one of the following exceptions applies, in which case the batter may leave the batter's box but not the dirt area surrounding home plate: (i) The batter swings at a pitch; (ii) The batter is forced out of the batter's box by a pitch; (iii) A member of either team requests and is granted "Time"; (iv) A defensive player attempts a play on a runner at any base; (v) The batter feints a bunt; (vi) A wild pitch or passed ball occurs; (vii) The pitcher leaves the dirt area of the pitching mound after receiving the ball; or (viii) The catcher leaves the catcher's box to give defensive signals. If the batter intentionally leaves the batter's box and delays play, and none of the exceptions listed in Rule 6.02(d)(1)(i) through (viii) applies, the umpire shall award a strike without the pitcher having to deliver the pitch. The ball is dead, and no runners may advance. The umpire shall award additional strikes, without the pitcher having to deliver the pitch, if the batter remains outside the batter's box and further delays play. Rule 6.02(d)(1) Comment: The umpire has the discretion to issue a warning to a batter in lieu of calling an automatic strike for the batter's first violation of Rule 6.02(d)(1) in a game, so long as the batter's violation is judged to be brief and inadvertent. The umpire shall give the batter a reasonable opportunity to take his proper position in the batter's box after the umpire has called a strike pursuant to Rule 6.02(d)(1) and before the umpire calls a successive strike pursuant to Rule 6.02(d)(1). (2) The batter may leave the batter's box and the dirt area surrounding home plate when "Time" is called for the purpose of (i) making a substitution; or (ii) a conference by either team. Rule 6.02(d) Comment: Umpires shall encourage the on-deck batter to take a position in the batter's box quickly after the previous batter reaches base or is put out.

The World Umpires Association also signed off on these changes.

"These strides to hone the pace of game over time will improve the natural rhythm of baseball, and we applaud and support the Players Association and the Commissioner's Office as we all move toward this goal," said Brian Lam, who represents the arbiters.

Phillies catcher Carlos Ruiz said hitters will have to make a big adjustment.

"Every hitter is different, has his superstitions," Ruiz said. "They step back, they take a break. But if it's the rule, you have to follow it. We'll have to start working on it in Spring Training and see how it goes.

"You have to prepare for an at-bat. You have to get ready for a pitch, and then you have to think about staying at home plate. It's going to be an adjustment."

Phillies manager Ryne Sandberg, the 1984 National League MVP Award winner with the Cubs, agreed that this represents a major change for hitters.

"That will take some time," Sandberg said. "I think there will have to be some reminders there. Practicing it through Spring Training will be a help. But there are some hitters who like to step out and do some things. They'll have to change their routines."

The second component will be the installation of timers on or near the outfield scoreboard and on the façade behind home plate. Immediately following the third out of an inning, the timer will count down from two minutes and 25 seconds for locally televised games and two minutes and 45 seconds for national games.

With 40 seconds left, the batter will be announced and his walk-up music will begin. With 30 seconds remaining, the pitcher will throw his final warm-up pitch. The hitter is expected to be in the box with between five and 20 seconds left so the game can resume immediately after the break.

Exceptions to these rules will be made in a variety of circumstances, including if the pitcher or catcher ended the prior half-inning at bat or on base. These rules will be enforced through a warning and fine system, with discipline resulting for flagrant violators. No fines will be issued in Spring Training or in April 2015.

"The Pace of Game Committee wants to take measured steps as we address this industry goal to quicken the pace of our great game. It is not an objective of ours to achieve a dramatic time reduction right away; it is more important to develop a culture of better habits and a structure with more exact timings for non-game action," Schuerholz said.

Clocks to make sure pitchers took no longer than 20 seconds between deliveries were used in the Arizona Fall League last year and will be utilized in Double-A and Triple-A this season. There are no immediate plans to have pitch clocks in the Major Leagues, however.

Finally, managers will no longer have to walk onto the field to issue a challenge. He may, however, hold play from the top step while waiting for feedback from the video tech whether or not to challenge. To challenge an inning-ending call, however, managers will be required to leave the dugout immediately in order to hold the defensive team on the field.

"After a year of just going out there and biding time and having friendly conversations with an umpire ... I think we got tired of going through that whole charade," Sandberg said. "I used to take my time going out there. To just get to the top step of the dugout and hold play for a second and then get the replay, which takes about 10 or 12 seconds, I think that's all good. I think it's all for the betterment of the game.

"At the end of the day, the umpires want to get plays right, because everybody sees it on the replay."

Other tweaks include the ability to challenge whether a runner left the base early or properly touched a base on a tag-up play. A manager must use a challenge in order to review whether a play at home plate included a violation of the rule governing home-plate collisions. However, in the event that a manager is out of challenges after the start of the seventh inning, the crew chief may still choose to review whether there was a violation of the rule.

During regular-season tiebreaker games, postseason games and the All-Star Game, managers will now have two challenges per game instead of one. And instant replay will not be utilized in the Grapefruit or Cactus Leagues, but it will be in place for exhibition games at Major League ballparks prior to the start of the regular season.