Kerr was called up from Triple-A El Paso on Friday, Dennis Lin of The Athletic reports.
The 27-year-old was acquired by the Padres in November and missed out on the Opening Day roster, but he'll join the big-league club Friday with Pierce Johnson (elbow) landing on the injured list. Kerr split the 2021 campaign between the Double-A and Triple-A levels, and he had a combined 3.18 ERA, 1.06 WHIP and 60:16 K:BB across 39.2 innings.