Diamondbacks manager Torey Lovullo said Monday that Sewald (oblique) will begin a rehab assignment Tuesday with Triple-A Reno, Theo Mackie of The Arizona Republic reports.
Sewald sustained a Grade 2 left oblique strain late in spring training and has been on the 15-day injured list all season. The right-hander will likely need multiple rehab outings before he makes his way back to the majors. Kevin Ginkel has done a fine job filling in as the Diamondbacks' closer, but Sewald should eventually get his old job back.