Thames was reassigned to Triple-A Las Vegas on Monday, Matt Kawahara of the San Francisco Chronicle reports.
Thames' minor-league deal with the Athletics seemingly put him in the best possible position to win a roster spot given the team's lack of alternatives at the position, but his .227/.346/.409 line in 11 spring games evidently wasn't good enough to earn him a job. Chad Pinder and Seth Brown could be the top options at first base heading into the start of the regular season, though the job could also go to non-roster invitee Billy McKinney.