Hernandez has gone 15-6 with a 3.66 ERA in 167 innings in 26 starts this season, but struggled in August. Though he won his last outing against Oakland at Safeco Field with a strong eight innings, allowing just three hits and two runs, he's just 3-3 with a 7.12 ERA over his last six starts.
McClendon employed a similar strategy last year when he gave Hernandez a few extra days' rest in late August, allowing him three extra days between starts before the stretch run. And the veteran posted a 2.40 ERA over his remaining seven outings in 2014.
Hernandez figures to have six starts remaining this year if the Mariners stay in rotation.
Hisashi Iwakuma will start Friday's series opener against the A's.
• Veteran left-hander Joe Beimel threw one inning of relief for Triple-A Tacoma on Sunday in his first rehab outing since going on the 15-day disabled list with shoulder fatigue on Aug. 20. McClendon said Beimel's outing was "just OK," and the 38-year-old will have another outing, likely on Tuesday, before a decision is made on his possible return on Friday.
• The Mariners will add four players from Tacoma on Tuesday when rosters can be expanded for September, though McClendon declined to offer any specifics. Center fielder James Jones and shortstop Chris Taylor seem like logical additions in the early wave following Monday's trade of Austin Jackson, with more to be added when Tacoma's season ends on Sept. 7.
• Jesus Montero was named to the All-Pacific Coast League team at first base after hitting .346 with 16 homers and 75 RBIs in 93 games for Tacoma. He's the first Rainiers player named to the All-PCL squad since catcher Rob Johnson in 2008.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB, read his Mariners Musings blog, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.