But since being named the closer on May 20, Chapman has been especially dominant, striking out nine in 5 2/3 innings of work and not giving up a hit.
"He just had to graduate mentally and psychologically into that role," manager Dusty Baker said.
On Friday against the Astros, Chapman picked up a save and finished off three strikeouts with fastballs, two of which registered a 100-mph reading on the stadium gun. He hadn't struck out the side in a one-inning appearance this season.
"If he can get by with fastballs -- I tell the guys -- why throw something else?" Baker said.
Baker will definitely use his relief ace whenever he needs him, but he will also monitor Chapman's strength and be sure not to use him too often.
"He's not the same after a couple consecutive days," Baker said.
Chapman has pitched in back-to-back games three times this season, all coming since May 16. As the closer, Chapman has pitched in back-to-back games once -- on May 22-23.
He's pitched in three consecutive games only once in his career: from Sept. 9-11 in 2010. Baker said he couldn't foresee using Chapman in three consecutive games.
"Unless we just have to," Baker said.