Miller was sent outright to Triple-A Iowa on Monday.
Musgrove (elbow) will make his next rehab start at Triple-A El Paso on Thursday, Jeff Sanders of The San Diego Union-Tribune reports.
The Padres transferred Giolito (elbow) to the 60-day injured list Monday.
The Padres optioned Song to Triple-A El Paso on Monday.
Pivetta (forearm) will resume a rehab assignment with Single-A Lake Elsinore this week, Annie Heilbrunn of The San Diego Union-Tribune reports.
Rengifo is not in the lineup for Monday's contest versus the Pirates.
The Padres selected Harris' contract from Triple-A El Paso on Monday.
Steele (elbow) is hoping to start a rehab assignment after throwing two more live bullpen sessions, Taylor McGregor of Marquee Sports Network reports.
Suzuki went 2-for-3 with three runs scored, three walks and a stolen base in Sunday's 19-2 win over the Mariners.
Imanaga did not factor into the decision Sunday, allowing two runs (one earned) on five hits, two walks and a hit-by-pitch over two-plus innings against the Mariners. He struck out four.
