"Don't think it's anything serious," Tigers manager Brad Ausmus said of Castellanos' injury. "It was a little sore. ... Just took the safe route and got him out of there.
"Nick probably could've played, if he was forced to. It's not a big concern."
Suarez's injury, which is being called lower back soreness, became worse in the third inning when he bent down to field a grounder. Suarez made a throwing error after fielding the ball.
He originally aggravated his back, feeling a "pinch," as he described it, on Alexei Ramirez's first-inning groundout. Suarez exited the game in the fourth inning, when Andrew Romine pinch-hit for him.
"I will try to play tomorrow," said Suarez, who is listed as day to day. "Right now, it hurts a little bit."
Matt Slovin is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.