Semien was scratched from the lineup for Game 2 of Saturday's doubleheader against the Astros.
Semien went 0-for-3 during the matinee and was initially listed in his usual starting spot for Game 2, but the A's then released a revised lineup. No reason has been given for his removal. Matt Chapman will shift to shortstop for the nightcap, while Vimael Machin starts at third base.