Pitchers will be ejected and suspended for 10 games for using illegal foreign substances to doctor baseballs in a crackdown by Major League Baseball that will start Monday.

The commissioner's office, responding to record strikeouts and a league batting average at a more than half-century low, said Tuesday that major and minor league umpires will start regular checks of all pitchers, even if opposing managers don't request inspections.

Repeat offenders will receive progressive discipline, and teams and club employees will be subject to discipline for failure to comply.

Umpires will perform period checks of all starting and relief pitchers on both teams throughout each game, MLB said. Starters will be subject to more than one mandatory check each game and relief pitchers must be checked once they conclude an inning in which they entered a game or when they are removed from a game, whichever comes first, MLB said. Catchers will be subject to routine inspections and position players may be searched.

Pitchers will be responsible for foreign substances found on catchers and position players. A position player will not be ejected for possession of a foreign substance unless the umpire determines the player was applying it to a ball to aid a pitcher.

Violators are subject to ejection and decisions are not subject to replay review. Players who refuse to cooperate with an inspection will be presumed to be in violation of the rules and subsequently ejected and suspended. Club employees who assist players in using or masking foreign substances or who refuse to cooperate or who fail to report violations will be subject to fines and suspensions.

Players suspended for violations will not be replaced on the active roster.

Rosin bags will continue to be allowed but rosin cannot be combined with sunscreen or other substances, and pitchers are being told not to use sunscreen after sunset in outdoor stadiums and not to use it at all in indoor ballparks. Umpires will inspect rosin bags before games to make sure they are standard.

"After an extensive process of repeated warnings without effect, gathering information from current and former players and others across the sport, two months of comprehensive data collection, listening to our fans and thoughtful deliberation, I have determined that new enforcement of foreign substances is needed to level the playing field," commissioner Rob Manfred said in a statement.

"I understand there's a history of foreign substances being used on the ball, but what we are seeing today is objectively far different, with much tackier substances being used more frequently than ever before. It has become clear that the use of foreign substance has generally morphed from trying to get a better grip on the ball into something else -- an unfair competitive advantage that is creating a lack of action and an uneven playing field.''

MLB told teams on March 23 it would increase monitoring and initiated steps that included collecting balls taken out of play from every team and analyzing Statcast spin-rate data.

"Based on the information collected over the first two months of the season -- including numerous complaints from position players, pitchers, umpires, coaches and executives -- there is a prevalence of foreign substance use by pitchers in Major League Baseball and throughout the minor leagues,'' MLB said.

"Many baseballs collected have had dark, amber-colored markings that are sticky to the touch. MLB recently completed extensive testing, including testing by third-party researchers, to determine whether the use of foreign substances has a material impact on performance. That research concluded that foreign substances significantly increase the spin rate and movement of the baseball, providing pitchers who use these substances with an unfair competitive advantage over hitters and pitchers who do not use foreign substances, and results in less action on the field.

"In addition, the foreign substance use appears to contribute to a style of pitching in which pitchers sacrifice location in favor of spin and velocity, particularly with respect to elevated fastballs. The evidence does not suggest a correlation between improved hitter safety and the use of foreign substances.''

The anticipated clampdown already appears to have had an impact.

Fastball spin rates averaged 2,306-2,329 revolutions per minute each week from the start of the season though June 5, according to MLB Statcast data.

Following an owners' meeting on June 3 when talk of a crackdown emerged, the average declined to 2,282 during the week of June 6 and dropped to 2,226 on Sunday.

The major league batting average was .232 through April, down from .252 two years ago and under the record low of .237 set in 1968, and it was .236 through May, its lowest since 1968.

The average rose to .247 in the week of June 6, lifting the season average to .238.

The strikeout percentage since June 3 is 23.4%, down from 24.2% until then, and the walk percentage is 8.4%, down from 8.9%.

"This is not about any individual player or club, or placing blame,'' Manfred said. "It is about a collective shift that has changed the game and needs to be addressed. We have a responsibility to our fans and the generational talent competing on the field to eliminate these substances and improve the game."

While Bill Miller, president of the Major League Umpires Association, was quoted as being supportive in the announcement, there was no similar statement from the Major League Baseball Players Association.

Some teams already have asked pitchers who relied heavily on foreign substances to throw bullpen sessions without any grip enhancers to prepare for the future, two players and an official told ESPN's Jeff Passan. Teams recently received reports from the league of pitchers on their team who had been caught using substances, two general managers told Passan.

That sort of preparation portends a change that already has taken root. Multiple pitchers, who asked for anonymity to avoid any punishment from the league, told Passan they either have stopped using foreign substances altogether or shifted from Spider Tack to pine tar -- from a relatively new and controversial product to one whose place in baseball dates back decades.

The Associated Press contributed to this report.