Miller was diagnosed with a left forearm strain, according to the club, and his status is considered day-to-day at this point. He had been in St. Louis to undergo an exam with team physician Dr. George Paletta after experiencing discomfort in his elbow.
"They [the medical staff] see a problem," manager Tony La Russa said. "We're just going to day-to-day it, see when he's available. I don't think he's available [Thursday], for example. ... We'll just use right-handers that can get left-handers out."
The good news is that Miller's fellow lefty specialist, Dennys Reyes, is available. Reyes spent time on the disabled list in August with elbow discomfort, but has been activated and is feeling better. La Russa said that even after pitching on Wednesday, Reyes could be available again on Thursday.
Three days in a row might be a push for Reyes at this point, but he's essentially as available as ever.