That takes Mills out of the running for Tuesday's start and means that he won't get another turn despite hurling five shutout innings in a win over the Orioles on Sunday.
"I'm surprised. I'm disappointed," Mills said. "I never know the circumstance, so I don't know if I was being sent down no matter what, if it had the chance of being an extended look. Obviously, there was a lot of other factors going on, but I want to be up here, I want to stay up here. I'm kind of at the point in my career where I've gotten enough spot starts in little stretches here and there. I want an extended look."
The move also appears to open the door for Garrett Richards to start in place of Dan Haren on Tuesday, but Richards gave up 12 runs in 8 2/3 innings over his last two starts for the Angels and struggled in his first start back with Salt Lake on Thursday, charged with eight earned runs in 3 1/3 innings.