SAN DIEGO -- Pitcher Tim Stauffer's simulated game Tuesday at Petco Park served a dual purpose, as he was able to test his right elbow against live hitters, such as outfielder Carlos Quentin who, like Stauffer, is attempting to get back from the disabled list.

Stauffer tossed three simulated innings before the Padres faced the Nationals. He sat down between innings in order to simulate what he would do if he were pitching in a game.

He also got to face Quentin, who is working his way back from arthroscopic surgery on his right knee on March 19.

Stauffer, on the disabled list since April 5 with a strained right elbow, will throw a normal side session on Thursday at Petco Park. If he comes out of that fine, he'll make a rehabilitation appearance with Class A Lake Elsinore.

"He's still getting the rust out a little today," Padres manager Bud Black said of Stauffer. "... His arm feels better than anytime this spring. He feels like he's throwing the ball like he should. With rest, he feels he is in a good spot."

There's still no projected date for the start of Quentin's rehabilitation appearance, Black said.

"He still has some things he needs to do to go play in a game," Black said. "Run the bases, sliding ... he's still got to pass those. We haven't challenged him to the point of high exertion yet."

Black wants Padres to improve on defense

SAN DIEGO -- The Padres entered Tuesday's game against the Nationals tied with the Orioles and Giants for the most errors (19) in the Majors.

The Padres have made errors in 11 of their first 17 games, including a season-high three during their 6-1 victory over the Phillies on Sunday.

"We've made too many errors this season," Padres manager Bud Black said. "Our guys are upset about the defense. We'll continue to work on it."

Run prevention has been the calling card of Black's teams since he took the job before the 2007 season. Last season, the Padres ranked ninth in MLB in fielding percentage (.985). During their 90-win season of 2010, the Padres had the second-fewest errors in baseball (72).

On Sunday, right fielder Will Venable had an error and rookie first baseman Yonder Alonso made two on the same play.

"Yonder is a young player who wants to do well," Black said. "I told him that if you make a mistake, you don't want to compound it."