CLEARWATER, Fla. — Major League Baseball chose not to implement a pitch clock for this season when it introduced rule changes Monday meant to speed up the pace of play after games reached record lengths last season.

MLB instead issued rules that limit mound visits to six per team during a nine-inning game and kept in place the countdown clock between innings and the rule that keeps batters in the box. A nine-inning game finished in an average of 3 hours and 5 minutes, an all-time high, in 2017. The games required 18 more minutes than they did in 1990.

The pitch clock was introduced in 2015 in minor-league baseball. The clock gave pitchers 20 seconds to throw a pitch, or else they were charged with a ball. A batter was issued a strike if he stepped out of the batter's box in the final five seconds. There was a thought that it would be coming to the majors this year. MLB said it had "decided to defer" the clock issue this season.

"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 players," MLB commissioner Rob Manfred said.  "My strong preference is to continue to have ongoing dialogue with players on this topic to find mutually acceptable solutions."