Luke Gregerson (oblique) is tentatively scheduled to begin a minor league rehab assignment Friday with Triple-A Tucson. Gregerson still has to make it through a bullpen session Wednesday without any setbacks. He's expected to make two appearances before being reevaluated, so it's possible he could be back with the Padres next week. The 27-year-old right-hander has been sidelined since June 9 with a strained left oblique.