Seattle Mariners pitcher Hector Santiago has been suspended 10 games and fined an undisclosed amount for a foreign substance found on his glove against the White Sox on Sunday. Santiago, who plans to appeal the ruling, will be allowed to play until the appeal process is complete.

The 33-year-old Santiago is the first player to be ejected for pitch doctoring since MLB began enforcing the new rules against foreign substances. The new rules included umpire checks on pitchers every few innings.  Umpire Phil Cuzzi found a sticky substance on Santiago’s glove when he was checked after being taken out in the fifth inning on Sunday. The glove was then put in a plastic bag by an MLB authenticator for testing.

Santiago has denied using any illegal substance, saying he was using rosin on his pitching hand, which is allowed. However, it’s only allowed on a pitcher’s throwing hand, not their glove. Santiago said on Sunday: “Once they take it back and check it, it’s just sweat and rosin. If they’re going to do all this science stuff, it’s going to be sweat and rosin. We’ll be all right.