Bob Nightengale

USA TODAY Sports

PHOENIX -- Major League Baseball Commissioner Rob Manfred, angered and frustrated that the players union will not accept any rule changes for the 2017 season, threatened Tuesday to unilaterally impose new rules in 2018 if an agreement can’t be reached.

Manfred wants to implement a pitch clock, limit mound visits and change the strike zone, and if the Major League Baseball Players Association won’t agree to the changes next year, he said the new labor agreement empowers MLB to apply the new rules in 2018 without union approval.

MLB union chief Tony Clark: Rule changes unlikely, Yankees' Levine 'unprofessional'

The commissioner came out swinging like no other time since taking office two years ago.

“Unfortunately, it appears there won’t be any meaningful change for the 2017 season due to a lack of cooperation from the MLBPA,” Manfred said. “I’ve tried to be clear that our game is fundamentally sound, and it does not need to be fixed.

“At the same time, I think it’s a mistake to stick our head in the sand and ignore the fact that our game has changed, and continues to change.”

Manfred was peeved about MLBPA executive director Tony Clark’s remarks Sunday in which he said there would not be any radical rule changes made in 2017.

“I have to admit that I’m disappointed we could not even get the MLBPA to agree to modest rule changes — like limit trips to the (pitcher’s) mound — that had little effect on the competitive character of the game,” Manfred said.

Clark certainly took exception to Manfred’s comments and said rule changes already are expected to be implemented this season. There are plans for a two-minute limit this year for instant replay reviews. Pitchers can now signal for an intentional walk. And there will be pace of game warnings and fines.

“Unless your definition of ‘cooperation’ is blanket approval,” Clark said in an e-mail to USA TODAY Sports, “I don’t agree that we’ve failed to cooperate with the Commissioner’s office on these issues. Two years ago we negotiated pace of play protocols that had an immediate and positive impact. Last year, we took a step backward in some ways (with the time of game increasing four minutes) and this offseason, we’ve been in regular contact with MLB and with our members to get a better handle on why that happened.”

Manfred, citing research, was alarmed that baseball had more inactivity during games than at any other time in history. Home runs were up 32% since 1980, and strikeouts increased by 67%. The emergence of powerful bullpens also limited the number of late lead changes.

“I’m firmly convinced that our fans want us to respond to and manage the change that’s going on in the game,” Manfred said. “I’m certain our job as stewards of the game is to be responsive to fans, and I reject the notion that we can educate fans to embrace the game as it’s currently been played.”

Manfred made it clear he still wants to receive the union’s approval and they will negotiate during the season. Yet if they continue to be rebuffed, the changes can be made despite the union’s disapproval, according to Article XVIII of the Basic Agreement, permitting rule changes within a two-year window.

“I would be surprised if those discussions with MLB don’t continue, notwithstanding today’s comments about implementation,” Clark said. “As I’ve said, fundamental changes to the game are going to be an uphill battle, but the lines of communication should remain open.”

Clark, who addressed reporters Sunday in Phoenix, said he thinks that dramatic rule changes are not needed in an industry expected to generate $10 billion in revenue this year. Attendance continues to hover around 75 million fans a year. The players are making more money than ever, an average of about $3.5 million a year, and the value of teams has soared to record levels.

Indeed, while the game has never been more healthy financially and perhaps never more popular, it’s no wonder Manfred’s public position could be uncomfortable, insisting the game must change to survive with the times.

“I’m glad the players love the game the way it is, but we know based on fundamental research what our fans think about the game,” Manfred said. “It’s in the players’ interest, it’s in our interest, to be responsible to what fans think about the game.”

Maybe, in time, change will be accepted by everyone. Perhaps if these rule changes are implemented over time, allowing them to first marinate in the minor leagues, they’ll be easier to digest.

“If you’re a traditionalist, the games run a certain way, and now you’re making some people do some uncomfortable things,” Oakland Athletics manager Bob Melvin says. “I think they’re doing the right thing in doing it incrementally and not doing it wholesale with multiple changes in a year; that makes everybody uncomfortable.’’

Yet no matter when it arrives, these rule changes are inevitable. Managers and general managers think it will start with the 20-second pitch clock, which alone could dramatically change the pace of games.

“If you go to a minor league game, you’ll notice the difference in how quickly the game is paced, because of the pitch clock,” Cleveland Indians GM Chris Antonetti says. “You don’t notice there’s a clock there, but you clearly notice the pace of the game is much quicker than in major league games.”

Finally, music to the commissioner’s ears.

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