Matheny said there was no timetable to get Maness into a game.
"I'm fine with the last couple of nights where we go seven or eight innings with our starter," Matheny said. "When you start trying to draw up how to get somebody in, you're probably setting yourself up for some trouble."
Matheny said the team did plan to use Maness, ranked the organization's No. 19 prospect by MLB.com.
"We didn't bring him here just to sit around," he said.
Joe DiGiovanni is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.