Royals catcher Salvador Perez took a hard foul ball to the mask Thursday afternoon in a game against thte Mariners. Later in the game -- after collecting an RBI single actually -- he was removed from the game.

The Mariners told reporters at the game (Bob Dutton) that Perez was removed from the game for precautionary reasons due to "mild dizziness."

The obvious concern here is another concussion. Perez was on the 7-day concussion DL less than a month ago. We know that foul balls to the mask can cause concussion-like symptoms as several other catchers -- such as Alex Avila of the Tigers -- have had the same issue.

If Perez is lost for any time it would be a bad blow for the Royals. The All-Star is hitting .286/.320/.419 with 22 doubles 10 homers and 64 RBI this year. More importantly though he's a very solid defensive catcher who works well with the pitching staff leading the AL in team ERA.