On Tuesday, Chapman lasted two-thirds of an inning and gave up five runs and four hits with one walk, one hit batter, one wild pitch and one strikeout. He threw 33 pitches.
"He obviously wasn't terribly sharp," Reds manager Bryan Price said. "He got hit, walked a couple of guys, hit a guy, so it wasn't an excellent outing. We would like him, when we activate him, to be ready to go. We'll make an assessment, I'm sure, in the next couple of days."
The Reds had expected Chapman to have four rehab outings as he prepared to return from being hit on the face by a line drive March 19. His first two appearances were a combined two scoreless innings for Class A Dayton last week.
Last weekend, Price anticipated that Chapman could be ready for activation from the disabled list on Friday, when the Reds open a three-game series at home against the Rockies.
Price wasn't ready to make that commitment until first speaking with Louisville manager Jim Riggleman and Bats pitching coach Ted Power.
"When we activate him, he's activated. We want to make sure that he's right," Price said. "We don't want to activate him prematurely. So we'll get some feedback, and talk to Chappy when we see him and see where he's at."
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.