ANAHEIM -- Angels superstar Mike Trout underwent both an MRI exam and a CT scan on his back after leaving Tuesday’s game against the Astros with upper back spasms; the results came back clean without showing a strain.

Trout was out of the lineup on Wednesday and is considered day to day. Jo Adell was recalled from Triple-A Salt Lake to provide depth with Trout out, while outfielder Monte Harrison was designated for assignment.

Trout said he had been dealing with some back discomfort for the last week or so and that it started to spasm on Tuesday, which forced him to leave the game in the fifth inning. But Trout said he felt better on Wednesday and was hopeful he’d be available to pinch-hit. He’s expected to be available to play against the Dodgers this weekend and it shouldn’t affect his status for the All-Star Game at Dodger Stadium.

“I feel a lot better than last night,” Trout said. “It just spasmed up on me and wasn’t getting any better. But it feels better today and I’m getting treatment. Hopefully I’ll be ready to pinch-hit if I need to. I’ve been dealing with it for a little bit now. Just trying to calm it down every day at the ballpark. It just got to a point where it was bothering me and was really uncomfortable.”

Angels head athletic trainer Mike Frostad said the first time he heard about Trout's back issue was last week when the club was in Miami. He said Trout has been getting daily treatment on his back.

“He just had some soreness in the middle of his back, and last night [it] got to be a little bit too much for him with the muscles tightening up and spasming on him a little bit,” Frostad said. “We did some testing on him and everything came out good. We’re hoping it’s just a soft-tissue injury and it’s just a day or two that he’ll be down.”

With Trout out, the Angels called up Adell, who was hitting .239/.333/.587 with 13 homers and 33 RBIs in 40 games with Salt Lake. The former top prospect has also batted .250/.276/.417 with three homers and 10 RBIs in 25 games with the Angels this year. He had been heating up at Triple-A, batting .321/.406/.750 with six homers and 16 RBIs over his last 14 games. He started in right field against the Astros with Taylor Ward in center and Brandon Marsh in left.

“It feels good,” Adell said. “I’ve had a process the last couple weeks that I’ve been really confident about. Hopefully, it’ll come out and help this team win. I’ve continued to find things that work for me. I’ve been feeling really good at the plate. Just hunting my zone and knowing where my zone is. There was a couple weeks where I scuffled a bit, but even that had to do with some luck. So I felt good about those at-bats too.”