The centerfielder was injured making a diving catch in right-center on a sinking liner hit by Pedro Feliz.
Pittsburgh manager John Russell called the injury a mild sprain of the AC joint and said McCutchen would be evaluated Monday.
"After it first happened, I didn't really know what to expect, but the X-rays were negative so we will see how it goes tomorrow and go from there," said McCutchen, the team leader in average, runs and steals.
The Pirates beat the Astros 9-0 one day after torching Houston for 17 hits in a 12-6 victory.
McCutchen is a former first-round pick who finished fourth in National League rookie of the year voting last season.
The Associated Press contributed to this report.