PHOENIX -- Rookie outfielder George Springer was out of the Astros' lineup with right knee soreness for the second straight game on Tuesday.
Springer missed Monday's 4-3 win against the D-backs as well, and he said before Tuesday's game that he thought could step in if needed.
"If I can breathe, I can play," Springer said.
Manager Bo Porter said Springer told him that he felt better than he did on Monday, and Springer thought that he may be available to pinch-hit.
"We'd just rather be safe than sorry," Porter said. "We'll let it subside and get treatment. The fact that he feels a whole lot better today than he did yesterday is even better news."
Springer was named the American League Rookie of the Month for May after hitting 10 home runs and batting .294. He leads the Astros with 35 RBIs.
"We'll get home tomorrow and let him get running around a little bit," Porter said. "If we don't have any ill effects, he'll be back in there."
Adam Lichtenstein is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.