Seattle Mariners pitcher Hector Santiago's 10-game suspension upheld, sources say

Seattle Mariners left-hander Hector Santiago's 10-game suspension for having a foreign substance on his glove has been upheld after an appeal, sources tell ESPN's Kiley McDaniel and Jeff Passan.

Santiago was the first and only pitcher so far to be ejected and subsequently suspended after Major League Baseball's crackdown on pitchers using sticky substances on baseballs.

The Mariners will not be able to fill Santiago's roster spot for the entirety of his 10-game suspension, per MLB's rules on pitchers using foreign substances.

Santiago was thrown out of the Mariners' 3-2 victory over the Chicago White Sox on June 26 in the fifth inning as he was being pulled from the game and the umpires…