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."