"Those were the two pitches where I felt something," Street said. "And I'm extremely thankful I didn't throw another pitch, because when you have something wrong with your muscle tissue and you throw another pitch at full speed, it's just way more damage."
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Street underwent an MRI and was diagnosed with a Grade 1-plus strain. (Grade 1 is regarded as the least severe, while Grade 3 is the most.) He dealt with the same injury when he was with the Padres in 2012 and spent one month on the disabled list.
The setback is particularly disheartening for Street, who is aiming to bounce back from an injury-marred 2016 campaign. He spent the offseason rehabbing from right knee surgery and also worked his body into better shape, shedding 15 pounds over the offseason.
"I put in a lot of really hard work this offseason, so it's obviously frustrating because you feel like maybe you deserve better," Street said. "But no sense in looking more than just that one day ahead. It's just a speed bump."
Street said he hopes his improved fitness will allow him to recover more quickly from the injury, unlike last season when he dealt with a nagging oblique issue that he believes altered his mechanics and eventually hurt his knee.
"I think the reason I couldn't come back from the oblique was I let my body get out of shape, which is on me," Street said. "And now hopefully, I will be able to come back from it. Because I think anybody would say it's the best shape I've been in in at least four years."
Street had entered the spring as one of three contenders for the Angels' closer job, alongside fellow right-handers Andrew Bailey and Cam Bedrosian.
"You don't want to see a situation where a guy puts in so much work in the winter time, not only with his own rehab but also his conditioning and how he approached everything [and then gets hurt]," Eppler said. "We're disappointed. I know he is as well, but he's got his mind in the right spot. He'll endure this, and he'll make it through."
Bailey pitched a scoreless inning in his spring debut Friday. Bedrosian, who was slowed by a tweaked groin earlier this spring, has yet to make a Cactus League appearance.