Kerkering will serve as the Phillies' opening pitcher for Sunday's game against the Athletics, Tim Kelly of PhilliesNation.com reports.

The Phillies reinstated Kerkering (forearm) from the 15-day injured list Sunday.

Kerkering (forearm) will be activated from the injured list before Sunday's game versus the Pirates, Matt Gelb of The Athletic reports.

Kerkering (forearm/illness) will make two more rehab appearances with Triple-A Lehigh Valley on Tuesday and Thursday before being activated, Luke Arcaini of Fox Sports PHL Gambler reports.

Kerkering (forearm/illness) will begin a rehab assignment at Triple-A Lehigh Valley on Saturday.

The Phillies placed Kerkering (illness) on the 15-day injured list Thursday with a right forearm strain.

Manager Rob Thomson said Saturday that Kerkering (illness) will begin the regular season on the injured list, Todd Zolecki of MLB.com reports.

Phillies manager Rob Thomson said Monday that Kerkering is still rebuilding his strength after a bout with the flu and might not be ready for Opening Day, Todd Zolecki of MLB.com reports.

The Phillies selected Kerkering from Triple-A Lehigh Valley on Friday, Matt Gelb of The Athletic reports.