"We discussed it, kind of where he was at going into the game, pitch-wise, and if he had enough to get through the next inning, but at that point it was probably best to go with somebody else," Servais said.
After striking out Stephen Vogt to escape a bases-loaded jam in the fourth, Hernandez settled down to retire 12 of the next 13 hitters. He allowed just three hits, while striking out 10 in a 99-pitch outing.
Joel Peralta came on to start the eighth and leadoff hitter Marcus Semien drove a 3-2 pitch over the left-field wall, leaving Hernandez with nothing more than an extremely well-pitched no-decision.
Hernandez, who is 22-8 with a 2.58 ERA in 41 career starts against the A's, said he did not lobby to remain in the game.
"We talked about it," the ace right-hander said. "It's early in the season. It's my second start. I had 99 pitches and I didn't want to throw 115 in my second start."
The fact that it was so early in the season played into the decision, Servais said.
"We do have a long season ahead of us," Servais said. "But, again, this was the top of his game today. It was fun to watch. The biggest thing, he really finishes hitters. He goes and gets them. He threw the ball really, really well."
Jim Hoehn is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.