Angels’ Mike Trout sidelined by upper-back stiffness

Reporting from Oakland —  Just when Mike Trout was heating up at the plate, the Angels’ center fielder was scratched from Saturday night’s game against the Oakland Athletics because of upper-back stiffness.

Trout, who is 15 for 33 with three home runs and 10 runs batted in over his last nine games, raising his average from .263 to .294, was originally scheduled to start at designated hitter.

But about two hours before the game, as the Angels were preparing for batting practice, Trout was removed from the lineup and replaced by C.J. Cron.

“It just came on today,” Manager Mike Scioscia said. “He has a hard time rotating. We were going to try to see if he could go out there and swing, but it’s just not quite loose enough to where you want him to risk any further injury.”

Trout sat out his first game of the season on May 21 because of some tightness in his left hamstring, but when he started the next eight games in center field, he appeared to have fully recovered from that injury.

Scioscia said Trout did not seem to tweak the back in any way during Friday night’s game. Scioscia was unsure of the severity of the issue, but it seemed doubtful Trout would be available off the bench Saturday night.

“Hopefully it’s something that quiets down, and he’ll be ready to go tomorrow,” Scioscia said. “He’ll get treatment on it, and we’ll see.”