Knehr was recalled from Triple-A El Paso on Saturday.
Knehr has posted a 7.84 ERA and 1.68 WHIP in 12 appearances with El Paso this season, but the Padres needed an extra arm with a couple pitchers landing on the COVID-19-related injured list, and Knehr got the call. If he does not pitch Saturday, there's a chance he could start the day after.