"The defense is not where we need it to be for the type of games we play, the tight, low-scoring games," said Padres manager Bud Black. "Especially playing at PETCO Park ... runs are at a premium."
Over their first 103 games last season, the Padres made 44 errors which helped account for 19 unearned runs. San Diego was 61-42 at that point in the season.
This season, the Padres were 45-58 after a 5-4 win over the Phillies on Monday. They had allowed 50 unearned runs and committed 68 errors.
"Heading into Spring Training, I felt our defense would be improved at every position expect first base ... that has not been the case," Padres general manager Jed Hoyer said.
"We have been much more mistake-prone this season, and it has cost us in many close games. It is a clear area of [needed] improvement as an organization."
Third baseman Chase Headley is the only returning infield starter from last season, as second baseman Orlando Hudson, shortstop Jason Bartlett and a host of first basemen are new. Bartlett finished Monday with 17 errors this season while Headley had 11.
The Padres' pitchers had a combined nine errors this season.
Black said defense is such a priority because San Diego plays so many close games and because its starting pitching staff relies more on ground balls than strikeouts. Going into Monday's game against the Phillies, the Padres starting pitchers had the eighth-best ground-ball percentage (58.3) in the Major Leagues.
"We're not going to lead the league in strikeouts ... we're not a strikeout-heavy staff," Black said. "I do think there's some strikeouts in our bullpen, but we know that there's going to be a lot of balls in play.
"We need to convert those into outs."