The moves came Sunday as the Orioles reached the 25-man limit. Machado is recovering from knee surgery and Reimold is returning from neck surgery
Baltimore also placed winter meeting draft pick Michael Almanzar and outfielder Francisco Peguero on the 15-day disabled list, put right-hander Edgmer Escalona on the 60-day disabled list and designated pitcher Mike Belfiore for assignment, opening room on the 40-man roster for reliever Evan Meek and outfielder Delmon Young, whose contracts were selected from Triple-A.
With Machado on the disabled list, rookie Johnathan Schoop and Steve Lombardozzi made the team as reserve infielders.
The Orioles open with 12 pitchers and 13 position players.