Quinn Harris/Getty ImagesHector Santiago, Seattle Mariners relief pitcher, has been officially suspended two days after he was the first to be ejected in accordance with Major League Baseball's policy regarding routine testing for foreign substances during games.MLB announced Santiago's 10-day suspension Tuesday, but noted that he will not begin serving it immediately as he has filed an appeal.Logan Gilbert was relieved by Santiago in the third inning.After 2.1 innings of pitching, the umpires arrived to inspect Santiago's glove. The umpires found some foreign substance on Santiago's mitt and he was thrown out of the game.Santiago said that he felt sticky stuff inside his glove after the 3-2 win in Seattle. "I used rosin. It was used on both sides to prevent sweat from getting down my hands.Tom Hallion, crew chief, told reporters Santiago had "a foreign substance sticky on his glove's inside palm." It was "very obvious."According to the MLB official guidelines, any pitcher found with or using foreign substances in violation will be expelled from the game and suspended automatically in accordance of past precedent and the rules.Santiago is now in his first season with Mariners, having signed a minor-league contract in May. Santiago was added to the Mariners' 26-man roster in May.The 33-year old has a 2.65 ERA and 23 strikeouts. He also allowed 13 hits in 17 innings in nine 2021 games.