Oakland's relievers have combined to pitch 27 2/3 innings over the past six games, including 6 2/3 on Thursday after starter Bartolo Colon surrendered eight runs in less than three innings.
Carignan departed Triple-A with the command he didn't have at the start of the season in Oakland. He had a 6.23 ERA in five games with the A's but proceeded to put together a 1.64 mark in Sacramento, where he struck out 17 and walked just one in 11 innings.
The decision to send down Miller was based on need, not performance, manager Bob Melvin said. The right-hander fared well in six relief appearances with Oakland, pitching to the tune of a 1.93 ERA and .229 opponents batting average.
"You look at his numbers, and he's thrown the ball really well for us," Melvin said. "I think he really opened some eyes here. Looking at the pecking order out of Spring Training, I don't think we envisioned him being at the big leagues at this point in time, and now he's on the roster and has jumped ahead of some guys. He made use of his stay here, and I wouldn't be surprised if he's back soon."
The A's still have just three right-handers in the bullpen, compared to four lefties.