"I'm trying too hard," Gonzalez said after striking out three times against the Marlins. "I am putting a lot of pressure on myself. ... It has been frustrating for the last three weeks."
Gonzalez's recent struggles at the plate essentially mirror those of his teammates. Over the last 15 games, the Padres have scored three or fewer runs 11 times, four times where San Diego has scored one or no runs in a game.
On Thursday, the Padres (48-37) went 0-for-8 with runners in scoring position, stranding a baserunner at third base with no outs in the first inning against Marlins starting pitcher Byung-Hyun Kim (4-4).
"I think the potential is there, it's not happening right now," manager Bud Black said of San Diego's offensive struggles. "I think we're seeing the signs of guys swinging the bats. ... Our situational hitting has not been what we expected."
Gonzalez, whose average has dropped from .306 on June 1 to .265 after Thursday's game, was one of Kim's strikeout victims in the first inning with Marcus Giles -- who drove in his brother, Brian, with a triple -- standing at third base.
Then, in the eighth inning, with Brian Giles at second base after a walk and a sacrifice bunt by Marcus Giles, Marlins reliever Armando Benitez ran a 3-2 slider past Gonzalez for the second out of the inning.
Gonzalez said his struggles are more mental than mechanical, though it was a flaw in his swing that he's fixed -- his hips were opening up too early, ruining his timing -- that first got the first baseman into his funk.
"Even my wife said my expressions at the plate have looked different," Gonzalez said. "I have gone about fixing it as much as I can. Everything feels great in the cage."
Gonzalez was one of the few Padres hitters who started the year strong, hitting .309 with seven home runs and 25 RBIs. He hit .284 in May and then .231 in June. So far in July he is 2-for-20 with nine strikeouts.
"He's pressing," Black said. "The way the first two months went, it hasn't gone his way the last month or so, and he's felt the burden of that."
Gonzalez felt especially bad that his inability to chase home a run -- he has one RBI in his last 15 games -- affected starting pitcher Jake Peavy (9-3), who came up short for the third straight time in trying to win his 10th game.
Peavy allowed three runs on five hits over seven innings with three walks. He didn't pitch poorly, though he would sure like to take back the home run he allowed to Florida's Jeremy Hermida -- on an 0-2 count no less -- in the fourth inning.
"The home run bothered me most because it was the pitch I didn't execute," Peavy said. "I threw it in a bad location and he hit a homer. ... That turned out to be the deciding run. That was tough to swallow."
The Padres turned two double plays behind him, but Peavy wasn't as dominant as he was against Florida May 6 when he took a no-hitter into the sixth inning.
"Overall, I thought Jake threw the ball fine," Black said. "Seven innings, three runs ... is still pretty good. I think we unfairly look, at times, for the spectacular out of Jake."
The Padres chased Kim in the seventh inning on Michael Barrett's RBI double, but San Diego couldn't get that run home as Jose Cruz Jr. struck out and pinch-hitter Josh Bard flew out to left field.
San Diego has now lost 17 one-run games this season, including 11 at PETCO Park.