Yankees assign three to Arizona Fall League
Williams, the team's No. 1 prospect entering the season according to several outlets, hit .261 with three homers, 24 RBI, and 15 steals in 100 games for Class-A Advanced Tampa before being promoted to Double-A Trenton in mid-August; he was 9-for-53 in 12 games for the Thunder through Monday.
Austin, who has spent the entire season in Trenton, hit .254 with six homers and 39 RBI in 311 at-bats for the Thunder before landing on the disabled list in mid-July; he began a rehab assignment in the GCL on Tuesday and should be returning to the Thunder for their push to the Eastern League postseason, but his assignment to Arizona is both to gain some extra at-bats and likely also see some action at first base, a position he has played sparingly throughout his time in the Minors but not at all in 2013.
O'Brien, drafted as a catcher in 2012, has already switched positions somewhat this season, seeing most of his time at third base since being promoted from Charleston to Tampa in late-June. He is hitting .288 with 20 homers and 88 RBI in 110 games between the RiverDogs and T-Yanks, and will likely continue his education at the hot corner while in Arizona.
The Yankees will send a total of seven players to the Arizona Fall League, with four pitchers to be announced at a later date.