Derrek Lee hit a ball off Maddux's left thigh in the first inning. Maddux retrieved it, made the out at first and went on to both bat and pitch in the second inning. However, due to pain from the hit, Maddux was replaced after that.
"The leg started to get a little stiff, and I came out," Maddux said. "It's one of those where, if it's April or May, you stay in."
Maddux said the pain in his thigh could have led him to alter his delivery had he stayed in.
"This kind of sets you back a little bit," he said. "I think I was supposed to go 60 pitches today, and I only threw about 30."
The injury is not expected to be serious, according to acting manager Craig Colbert.
"That was precautionary, the whole thing," Colbert said. "[Pitching coach] Darren [Balsley] just felt it would be the right thing."
Maddux allowed two hits in two scoreless innings, striking out one, and is 1-0 with a 1.29 ERA in three starts this spring.
Mark Thoma is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.