Colorado (65-73) lost 9-4 to the Padres (52-83) on Saturday, just its fourth defeat in the last 14 games. The Rockies, who won 14 of their final 15 games last season to make the playoffs, remained six games behind division-leading Arizona, which lost 6-2 to the Los Angeles Dodgers.

The Rockies have not been within five games of the NL West lead since April 21.

Last-place San Diego scored six runs in the fourth to erase a 2-0 deficit, then added three runs in the seventh en route to its fourth win in five games. The Padres are attempting to avoid 100 losses for the sixth time in team history and the first time since 1993

"(Padres starter Josh Geer) changed speeds and kept the ball out of the middle," Rockies manager Clint Hurdle said. "There wasn't enough in the recipe for us to win."

The Rockies will try to extend their recent success against Padres ace Jake Peavy (9-9, 2.84 ERA), who starts a day later than originally scheduled. Peavy was given an extra day of rest after he threw 121 pitches in his last start.

Peavy has a 2.70 ERA in three starts against Colorado this season, but is 0-2 in those outings, with San Diego losing all three after providing him with just three runs of support. The right-hander has lost his last four decisions against the Rockies since a win on Sept. 21, 2005 at Coors Field, compiling a 4.99 ERA in eight starts since his most recent victory.

Peavy, though, is 5-4 with a major league-best 1.54 ERA in 12 home starts this season. Despite outstanding work from its ace, San Diego has managed only a 6-6 record in those games.

He yielded two runs and four hits with seven strikeouts in six innings of a 4-2 home win over Arizona on Monday, but left without a decision.

Jeff Francis (4-8, 5.36) counters for Colorado.

Francis is 1-0 with a 2.84 ERA in his last three starts. On Monday against San Francisco, he won for the first time in more than two months, allowing two runs and seven hits over seven innings in a 4-2 victory.

"It's a good feeling," said Francis, who came off the DL earlier this month after being sidelined with left shoulder inflammation. "I'm making better pitches now than I was before. I'm commanding my fastball a lot better and I'm able to stay ahead in a lot more counts."

The left-hander is 5-10 with a 5.42 ERA in 17 starts against the Padres. He pitched seven scoreless innings versus them on April 17, allowing three hits in Colorado's 22-inning, 2-1 win.