Miller (elbow) threw 25 pitches of live batting practice Friday, the Associated Press reports.
The right-hander was facing hitters for the second time in three days and felt "fantastic" during Friday's session, according to manager Torey Lovullo. The Diamondbacks will likely limit Miller's activity for the next few days before allowing him to throw again as the club takes a cautious approach in bringing him back from May 2017 Tommy John surgery. A formal timeline for Miller's return from the 60-day disabled list hasn't been established, but the general expectation is that he'll be ready to handle a starter's workload at some point shortly before the All-Star break.