Mariners manager Scott Servais told reporters Sunday that Hernandez and Hisashi Iwakuma will both be activated from the DL in time for next weekend's series. Servais expects Iwakuma to start either Saturday or Sunday.
Hernandez, 31, has missed almost two months because of inflammation in his pitching shoulder. The six-time All-Star threw six shutout innings in a rehab start Saturday for Triple-A Tacoma.
The American League Cy Young Award winner in 2010, Hernandez was off to a rough start this season, going 2-2 with a 4.73 ERA in five outings before being placed on the DL in late April.
Iwakuma (shoulder) has been out since early May but will pitch for Tacoma on Monday. The right-hander is 0-2 with a 4.35 ERA in six starts this season.
The Mariners have been plagued by injuries to their rotation this season. Hernandez, Iwakuma and James Paxton all have had extended stints on the DL over the past seven weeks, and Drew Smyly (elbow) has been sidelined since late March with an elbow strain.