Irvin allowed two runs on six hits and no walks while striking out three over 4.1 innings in Thursday's Grapefruit League win over the Blue Jays.
The southpaw said he struggled early in the start as he was still experimenting with pitches, Nathan Ruiz of The Baltimore Sun reports. Irvin is expected to make two more appearances in Grapefruit League play, which will serve as more dedicated preparation for regular-season action. The 29-year-old is a virtual lock for the Orioles' rotation after posting a career-best 3.98 ERA and 1.16 WHIP with a 128:36 K:BB over 181 innings with the Athletics last season.