The Athletics outrighted Shuster to Triple-A Las Vegas on Wednesday.
Shuster was claimed off waivers by the Athletics in August but did not make an appearance for them at the big-league level. The 27-year-old was a full-time reliever for the first time in 2025 and posted an 8.04 ERA and 12:5 K:BB over 15.2 innings this year with the White Sox.