Two teams whose 2013 campaigns have not gone according to plan begin their first series of the season's final month Monday at Petco Park, where the Padres host the reigning World Series champion Giants in a Labor Day matinee.
The Padres and Giants -- just one game apart at the bottom of the National League West -- match right-hander Ian Kennedy and lefty Barry Zito in Monday's series opener.
Kennedy, who joined San Diego in a trade with Arizona in July, had a less-than-stellar homecoming against his former squad in his last start, allowing six runs and walking five in 4 1/3 innings.
"I just put myself in holes, putting guys on; I walked a lot of guys," said Kennedy, who is 2-1 with a 4.55 ERA in five starts with the Padres. "It's tough to do that."
One of the reasons San Diego was interested in the right-hander was his resume at Petco Park, where Kennedy is 5-2 with a 2.72 ERA in nine career starts.
Like Kennedy, Zito's 2013 campaign has been a struggle. The Giants veteran has only one winning decision in his last 19 starts, during which he's 1-9 with a 6.14 ERA. San Francisco shuffled its rotation to give Zito an extra day of rest, and he's 17-13 with a 3.78 ERA in 37 career starts under such conditions.
He has a 3.44 ERA in four starts against the Padres this season, though the Giants lost three of those games.
Giants: Bochy careful with Pagan
Center fielder Angel Pagan, who has missed most of the season following left hamstring surgery, did not start Sunday in Arizona. Manager Bruce Bochy said he plans to rest Pagan every few days.
Pagan is 2-for-7 with a double, two walks and a stolen base in two games since being reinstated from the disabled list on Friday.
"It's pretty impressive, [given] the extent of the injury, how well he's doing," Bochy said.
• San Francisco is hitting .306 with runners in scoring position in its last eight games.
Padres: Headley misses another game
Third baseman Chase Headley was out of the lineup for the fourth straight game on Sunday because of lower back stiffness that forced him out of Tuesday's game against the D-backs.
"The back is still bothering him," manager Bud Black said. "He was making progress, and that has sort of reached a plateau. He didn't quite make the progress in the next 24 hours that he did the first 24."
• The Giants lead the season series, 8-5.
• Monday's game continues a string of 20 straight for the Giants against the NL West.
Monday: Kennedy (5-9, 5.10 ERA) vs. Zito (4-10, 5.81)
Tuesday: LHP Robby Erlin (2-2, 5.97) vs. LHP Madison Bumgarner (11-9, 2.91)
Wednesday: LHP Eric Stults (8-12, 3.81) vs. RHP Tim Lincecum (8-13, 4.38)