Mengden won't start Saturday's game against the Mariners but will serve as the Athletics' primary pitcher after Liam Hendriks opens the game, Jane Lee of MLB.com reports.
Mengden was set to take over for Brett Anderson (forearm) in the starting rotation, but the Athletics will instead opt to use Hendriks as an opener. Mengden fired four scoreless innings while relieving Anderson on Monday and has a 4.47 ERA over 16 starts in the majors this season. It remains unclear if this is a one-time strategy for the Athletics or something they plan to utilize on a regular basis.