"I just didn't feel comfortable," Trout said of his back. "I didn't want to risk it by pushing it too much. ... I don't think it's that severe, but we'll see."
Trout, who was to be evaluated by a doctor Wednesday in Houston, is not in the starting lineup for Wednesday's game.
"He'll have some studies done," manager Mike Scioscia said, according to the Los Angeles Times. "I'm sure he's going to have some kind of an X-ray or something.
"We'll definitely take a half-step back here and find out exactly what's going on. He can't think of one thing that he did in the course of the last three or four days that caused it."
Trout said he wasn't "too concerned" about his back.
"[I] made progress over the last two days, so it was obviously getting better, but just don't want to push it too much where it gets worse," he said. "It's frustrating for me, I want to be out there."
Hamilton, the former AL MVP who returned from the disabled list Tuesday after breaking his left thumb while sliding headfirst into first base on April 8, homered in the eighth inning for the Angels.
Hamilton hit .444 with two homers and six RBIs in eight games for the Angels this season before getting hurt.
The Angels optioned right-hander Jarrett Grube to Salt Lake on Sunday to make room on the roster for Hamilton. They also selected the contract of right-hander Cam Bedrosian from Double-A Arkansas and optioned right-hander Michael Kohn to Salt Lake.
Bedrosian, a 22-year-old reliever, has a 1.47 ERA in 17 games this season for Arkansas.
The Associated Press contributed to this report.