WASHINGTON -- Shortstop Felipe Lopez left Sunday afternoon's game against the Cardinals with tendinitis in his right patella (kneecap). He is listed as day-to-day.

Lopez played the first five innings of the game and went 0-for-2 with a walk against St. Louis right-hander Adam Wainwright. For the season, he is hitting .243 with six home runs and 41 RBIs.

Lopez has been bothered by the problem for at least a week after bumping his knee on a table while playing with his daughters.

"The knee got inflamed," Lopez said. "It's nothing big. I just need a little rest."

Lopez is not sure if he will be able to play the opener of the four-game series against the Giants on Monday night.

"We'll see," he said. "It will depend on what the trainer has to say."