Earlier this month, MLB started its plan to go heavy handed with checking pitchers for the use of foreign substances. For the most part, we've seen pitchers and umpires kind of laughing through the exercise, though some have acted a bit dramatic about it.  Sunday, we got our first ejection. Mariners pitcher Hector Santiago was tossed in Seattle's game against the White Sox after the umpires inspected his glove.

"He was ejected for when his glove was inspected, for having a foreign substance that was sticky on the inside palm of his glove," crew chief Tom Hallion explained after the game. Hallion also termed the substance "very noticeable" and said all members of the umpiring crew agreed with the determination that it was a foreign substance. 

Here's a look at the ejection:

Under the crackdown, any sort of foreign substance anywhere on the pitcher, his glove, his hat, his belt buckle, etc. carries an automatic ejection. 

On Tuesday, MLB announced Santiago has indeed been suspended 10 games and fined an undisclosed amount for "possessing a foreign substance on his glove." Santiago is appealing the suspension and is eligible to play until the appeal is heard. Per Jayson Stark of The Athletic, MLB did not further inspect Santiago's glove after Sunday's game before issuing the suspension.

Santiago previously said it was "just sweat and rosin."

"Once they take it back and check it, it's just sweat and rosin," Santiago told reporters, including ESPN's Jesse Rogers, following Sunday's game. "If they're going to do all this science stuff, it's going to be sweat and rosin. We'll be all right."

As part of the foreign substance crackdown, the Mariners wouldn't be allowed to replace Santiago on the active roster while he serves his suspension, which means they would be down one pitcher spot for 10 games. In the past, many foreign substance suspensions were reduced from 10 games to eight games on appeal. 

David Samson discussed Santiago's ejection on Monday's Nothing Personal with David Samson. Listen below:

By way of reminder, Rule 6.02(c)(7) says: 

The pitcher shall not have on his person, or in his possession, any foreign substance. 

This rule has been on the books for decades, but things started to get out of control with pitchers taking far too much of the leeway they were given. As a result, MLB issued a memo in the spring to ramp down the use of substances and that didn't work, so the league mandated that umpires would start checking pitchers on the field, starting this past Monday.