On Friday, the 23-year-old was set to make his big league debut against the Baltimore Orioles.
Williams was recalled from Triple-A Scranton/Wilkes-Barre on Thursday, a day off for the Yankees.
Asked his reaction to the call, Williams said, ''I started sweating. I started sweating a lot.''
On his first day with the Yankees, Williams started in center field and batted ninth.
Williams was drafted in the fourth round of the 2010 draft by New York. Although he hit .223 with Double-A Trenton last year, he said he learned from the experience.
Now the time has come for Williams to shine.
Manager Joe Girardi said, ''He has really come quickly this year.''