Jayson Stark joins Mike & Mike to break down why baseball games are taking an average seven minutes longer this season than last season. (2:02)

The average time of a nine-inning baseball game is up nearly seven minutes compared with this point last season, and MLB commissioner Rob Manfred isn't happy about it.

"We think the single biggest thing we had going for us early in the year [last season] was player focus on the topic," Manfred told ESPN. "And we feel like we've lost a little focus. So we're doing a variety of things to try to get that focus back."

Through Monday, the average time of a nine-inning game this season was 3 hours, 26 seconds. At the same stage of last season, about six weeks after MLB implemented much-ballyhooed new pace-of-game rules, the average game time was 2:53:33. That pace did slow, however, and the average time by season's end wound up at 2:56:14.

Manfred said officials in the commissioner's office have reached out to the Major League Baseball Players Association to let the union know that they're "concerned" about this trend. And players identified as repeated violators of pace-of-game rules have actually received personal phone calls reminding them to adhere to the rules, sources say.

MLB officials believe the prolonged stretch of cold weather in the Midwest and Northeast is one factor, because "when it's cold," Manfred said, "the games do go longer."

Another factor, MLB has concluded, is a steep spike in pitches per game, which have risen to their highest level (289.25 per nine-inning game) in seven years. However, Manfred absolved baseball's replay system of blame, saying he looks at the 35 percent increase in replay reviews, compared with last year, as more of a pace-of-game issue than a time-of-game issue.

Even with the increase in total number of replays, baseball still averages less than one replay per game. So the rise in replays and the rise in game time don't appear to be related. Nevertheless, Manfred said, baseball is studying various aspects of replay this season and will look at potential tweaks to the system after this year.

Commissioner Rob Manfred is unhappy with the growing pace of MLB games this season and is focusing on measures to shorten games once again. AP Photo/Paul Sancya

"You can rest assured," the commissioner said, "that we are watching this year, and we will be analyzing during the offseason, both the number of replays and particularly the longer reviews. The 4-minute-and-50-second reviews don't make me that happy."

Manfred said he is actually gratified that the expanded replay system has worked so well over its first three seasons that MLB has "only tinkered at the edges with the system." Nevertheless, he said, the 35 percent rise in total replays and the trend toward longer reviews are issues "that merit analysis."

"Meriting analysis doesn't mean there ought to be a change," he said. "Just, they merit analysis."

The commissioner said he thinks baseball needs to look at "creative ways" to improve both time and pace of game. He promised that this will be a major topic this summer in negotiations over the next labor deal, which would take effect after this season. Baseball continues to experiment with pitch clocks in minor league games, but Manfred declined to say whether MLB would push for pitch clocks in the major leagues next season.

"We're going to put a package of issues on the table with the union," he said. "Speculating about which ones I like and don't like is counterproductive to that process at this point. I think the best I can do for you at this point is to say I'm prepared to think about additional rule changes that are relevant to the issue of pace of play."