The Brewers optioned Miller to Triple-A Nashville on Sunday, Curt Hogg of the Milwaukee Journal Sentinel reports.
Miller will retain a spot on the 40-man roster heading into Opening Day, but he'll fall short on winning a spot in Milwaukee's season-opening bullpen. The 28-year-old covered 10.2 innings at the big-league level with the Rangers in 2022, giving up 13 earned runs on 16 hits and eight walks.