Brentz cleared waivers and was assigned to Double-A Northwest Arkansas on Friday.

The Royals designated Brentz for assignment Monday.

The Royals activated Brentz (hamstring) from the 15-day injured list Monday and optioned him to Double-A Northwest Arkansas, Anne Rogers of MLB.com reports.

Brentz (hamstring) will begin a rehab assignment with Triple-A Omaha on Sunday.

Brentz (hamstring) thew a bullpen session Tuesday and remains on schedule, Byron Kerr of MLB.com reports.

The Royals placed Brentz (hamstring) on the 15-day injured list Thursday.

Brentz was diagnosed with a Grade 2 strain in his left hamstring Tuesday, Anne Rogers of MLB.com reports.

Brentz (lat) is listed as available for the Royals' Cactus League opener versus the Rangers, Anne Rogers of MLB.com reports.

Brentz (lat) threw a live BP session Saturday, Anne Rogers of MLB.com reports.

Brentz (elbow) is expected to miss the remainder of the season after suffering a left lat strain while on his rehab assignment, Anne Rogers of MLB.com reports.