Gregg served up a walk-off three-run homer to Kyle Blanks, part of a four-run ninth inning, as the Padres rallied for a 4-1 win over the Cubs, who dropped six games back in the National League Central.
This was not how the Cubs or Gregg wanted to start their seven-game West Coast trip.
"I wasn't pitching," Gregg said. "I went away from what I wanted to do and didn't execute my pitches, and it cost us the game."
With one out in the ninth, Gregg walked David Eckstein and then got Adrian Gonzalez, the recently crowned National League Player of the Week, to fly out to left. The right-hander felt pretty good about the situation.
"Two outs, you're right there, you're one pitch away from getting out of that inning," Gregg said.
But Chase Headley hit a game-tying RBI double into the gap in left-center. Kevin Kouzmanoff was intentionally walked, and Gregg then served up Blanks' homer on a 1-1 pitch. It's the 12th off Gregg this season; he gave up three home runs last season, and seven in 2007.
"I think we're going to make some changes as far as what we're going to do in late innings," Piniella said. "We'll have some word [Tuesday]."
An upset Gregg said he could understand Piniella's dissatisfaction with his performance.
"I've still got to get people out, it doesn't matter what I'm doing," Gregg said. "I'm not executing my pitches."
It's been a tough stretch. There were the back-to-back blown saves in Florida, with Gregg serving up home runs in both games. On Aug. 11, he gave up a game-winning homer to the Phillies' Ben Francisco in the 12th inning and the Cubs took the loss.
"They all end the same way with a home run ball," Piniella said.
Pitching coach Larry Rothschild was working with Gregg on adjusting his delivery because the Cubs thought he was tipping his pitches.
"I think it's taken some of my concentration away from what I'm trying to execute," Gregg said. "The bottom line is getting people out. It doesn't matter how you do it. If I throw underhand and get people out, I don't care. If they hit three line drives, I don't care. The biggest thing is getting people out."
The Cardinals were playing just up Interstate 5 against the Dodgers, and won, 3-2. That didn't help matters.
Is it something mechanical?
"It's a matter of just pitching," Gregg said. "It's just making stupid mistakes, seeing something in a hitter and not executing it when you see it, knowing a game plan against a hitter and not doing it."
It's not just bad location.
"Location is very important in this game," Gregg said, "but it's also sequences and how you use them. It's the right sequences and executing them as well."
After saving 61 games the past two seasons combined, Gregg is still confident.
"I still believe in my stuff," he said. "Now it's honing it in and getting back to where I was the last couple years."
But Carlos Marmol, Angel Guzman or John Grabow could be the closer in the next save situation.
The Cubs had taken a 1-0 lead in the eighth when Derrek Lee tripled to lead off and scored on Aramis Ramirez's single. For Lee, he's now hit safely in 19 of his past 24 games. This was Ramirez's first start since Aug. 8 after being sidelined first with a sore left shoulder and then with a sore throat.
But it wasn't enough to give Ted Lilly the win in his first start since July 20. The left-hander, sidelined because of inflammation in his shoulder, gave up four hits and one walk over six innings, striking out four. He was on an 85-pitch limit but was pulled after 70.
"Everything felt good," Lilly said. "Obviously, for me, it's nice to get back out there on the field. It seemed like it'd been a really long time."
The Cubs had opportunities, and stranded 10. You've probably heard that before.
"That was a tough one," Lee said. "We've got to swing the bats better. I had a great opportunity to drive in a run with a guy on third base [in the sixth] and we can't afford to leave a guy at third base.
"We haven't swung the bats, we haven't been consistent with the bats. One run isn't going to cut it. We had great opportunities. We've just got to do a better job."
How do the Cubs bounce back from this one?
"You win," Lilly said. "I thought we played good. Obviously, we didn't score too many runs, but our defense was good, real good."
Give Mike Fontenot credit for that. He showed his value in the Padres' sixth when he grabbed Gonzalez's hard-hit ball, spun, and threw to Aaron Miles at second to start a 4-6-3 double play.
Padres starter Kevin Correia did pitch well. But the Cubs now are 8-43 when scoring less than four runs. They're also 0-4 at PETCO Park.
"We're in a pennant race and we're not helping ourselves now," Lee said. "We can't afford to lose these games. It just can't happen."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.