"I don't think it's serious," Reds manager Bryan Price said. "He went in and had an X-ray. It's a contusion, definitely. He got hit hard with the baserunner sliding on the double steal. We were going to the back side throwing to second base. He took a helmet to the interior portion of his knee that was quite painful and uncomfortable. We'll reassess him tomorrow."
In the top of the second inning during his lone at-bat of the day, Phillips grounded out to the shortstop and jogged slowly up the line. He did not return for the bottom of the second and was replaced by Ivan De Jesus Jr. at second base.
This is the second injury in less than a week for Phillips, who missed Wednesday's game at St. Louis with a bruised right quadriceps. The 35-year-old has been banged up by multiple nagging injuries this season, which included his playing through a fractured left hand.
Phillips is batting .282 with eight home runs and 48 RBIs this season. He was 13-for-28 (.464) on the nine-game road trip and is batting .372 over his last 29 games.
Mark Sheldon has covered the Reds for MLB.com since 2006, and previously covered the Twins from 2001-05. Follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.