Major League Baseball is renewing its efforts to crack down on pitchers using foreign substances, according to MLB Network's Jon Heyman. The supposed forthcoming crackdown comes after Thursday's owners meeting, during which evidence was presented suggesting that ball doctoring was "very prevalent" throughout the league -- a statement that, if true, could help to explain the lowest batting average and highest strikeout rate in league history.

Heyman's report is but the latest note in a recent wall of sound relating to pitchers' use of foreign substances. In the past eight days, the following news items have surfaced:

May 26: Umpire Joe West confiscates the hat of St. Louis Cardinals reliever Giovanny Gallegos based on the suspicion that it is coated with a foreign substance. Gallegos was not ejected from the game, or otherwise punished by the league office.

May 26: In response to the Gallegos incident, Minnesota Twins third baseman Josh Donaldson tweets that he has an "entire catalog of video" of pitchers cheating. Donaldson hints that he's going to release it, though he offers no further details.

June 1: Chicago White Sox announcer (and former big-league pitcher) Steve Stone observes during a broadcast that Cleveland reliever James Karinchak appears to be doctoring the ball on the mound using a black-like substance on the thumb of his red fielding glove.

June 2: MLB suspends three minor-league pitchers for 10 games after they were ejected for having foreign substances on the mound. MLB had also suspended a fourth pitcher for 10 games earlier in the season. 

All of this stems in part from a league-issued memo in March wherein MLB announced new guidelines as it related to foreign substance use. The league indicated it would be investigating suspected ball-doctoring cases, even if it meant confiscating playing gear, having a third-party lab test for illicit substances, and then punishing players after the fact. The league even said it would be using spin-rate analysis to determine who might be doctoring balls to gain an edge.

Still, no big-league pitcher has been punished for foreign substances as of this writing. Los Angeles Dodgers right-hander Trevor Bauer was reported to be under league investigation in April after balls used during his start were sticky and had visible markings. The league never issued its findings in that case, and it's unclear whether said investigation remains open.