Waldichuk will have his contract selected to start Thursday against the Nationals, Martin Gallegos of MLB.com reports.
It was reported earlier Tuesday that the left-hander would receive a call-up when the major-league roster expands to 28 players Thursday, and he'll immediately step into the rotation for Oakland. Waldichuck was acquired from the Yankees as part of the return for Frankie Montas, and the 24-year-old has a 3.53 ERA, 1.27 WHIP and 91:26 K:BB across 66.1 innings at the Triple-A level this year.