Decker cleared waivers and was outrighted to Triple-A Nashville on Saturday.
Decker was designated for assignment Tuesday.
Decker will bat seventh and start in center field against the Angels, MLB.com's Jane Lee reports.
Decker went 2-for-2 with a run and a walk in Thursday's 8-5 win over the Twins.
Decker is out of the lineup Sunday against the Astros.
Decker went 1-for-3 with a walk in Tuesday's 2-1 extra-inning loss to the Angels.
Decker will man center field and hit leadoff in Friday's game against the Mariners.
Decker is playing center field and leading off Tuesday against the Rangers, Jane Lee of MLB.com reports.
Decker went 3-for-4 with an RBI single, run and stolen base in Saturday's 10-6 loss to the Astros.
Decker's contract was selected by the A's on Saturday.