Luzardo was scratched from Wednesday's start for Triple-A Nashville, perhaps due to an innings restriction, Nashville Sounds' broadcaster Jeff Hem reports.
Luzardo has thrown 109.1 innings across High-A, Double-A and Triple-A this season after totaling 43.1 innings at rookie ball in 2017. The Athletics apparently have a ceiling of 125 innings for their young left-hander, Jane Lee of MLB.com reports, but at this point there has yet to be official confirmation that the 20-year-old has been shut down for the season.