The San Francisco Giants failed to pad their NL wild-card lead when their usually reliable bullpen had its worst performance of the season.
A four-game visit from Colorado that begins Monday night would appear to provide the ideal opportunity to get past that loss quickly - given the Rockies' recent road woes - but Colorado's only successful series away from home in the last four months was at AT&T Park.
San Francisco (68-61) had a five-run lead after three innings Sunday in Washington but allowed the Nationals to zoom past for a 14-6 rout. The Giants' bullpen was charged with season highs of 11 runs and 14 hits in 2 2-3 innings after entering with a 2.57 ERA, third-best in the majors.
"They've been terrific," manager Bruce Bochy said. "We turn it over to the pen and they do a great job. Our guys, I feel for them. They played so well early and that's a tough one to let get away."
Losses from Atlanta and Pittsburgh kept Bochy's club one game ahead of the Braves and 1 1/2 in front of the Pirates in the second wild card.
The Giants, winners in four of their last six home games, now face a club that's lost 23 of 26 on the road since sweeping a three-game set in San Francisco from June 13-15.
Colorado (52-77), coming off a 6-3 homestand in which it batted .322 and averaged 6.1 runs, had 14 hits in Sunday's 7-4 win over Miami, despite a pair of absences. Nolan Arenado, batting .529 in his last eight games, hit his third homer in that stretch.
The Rockies placed Michael Cuddyer on the disabled list with a sore left hamstring. Catcher Wilin Rosario missed Colorado's back-to-back victories with a sore left wrist but is hoping to return to the lineup Monday.
Jake Peavy (2-3, 3.58 ERA) will try to cool off the Rockies' lineup while earning his third win in as many starts. The right-hander, acquired from Boston on July 26, has yielded three runs in 14 innings in his last two outings after going 0-12 with a 5.25 ERA in his previous 18.
He gave up 10 hits in seven innings at the Chicago Cubs on Wednesday, but permitted just two runs and fanned eight in an 8-3 victory.
"We've got five or six more starts and I've got to try to find a way to win those with us trying to get in (the playoffs)," he said.
Peavy is 5-6 with a 4.10 ERA in 19 career starts against Colorado and gave up five runs in six innings in his most recent, a 15-5 victory for the Red Sox on Sept. 25 in Denver.
In his first start against San Francisco, Tyler Matzek (2-9, 5.38) will seek to avoid his sixth loss in as many appearances. He is 0-4 with a 7.89 ERA in four starts this month but pitched relatively well in Tuesday's 7-4 defeat to Kansas City.
The rookie left-hander was charged with three runs in 6 2-3 innings and two of those came from a double allowed by reliever Adam Ottavino.
"He did a nice job tonight, getting deep into the game," manager Walt Weiss said of Matzek. "So he's making strides."
Angel Pagan might get to face Matzek after sitting out Sunday's game with a tight left calf. Pagan is 8 for 24 in his last five games.
Hunter Pence has two homers and five RBIs in his last five contests, and is batting .409 with four home runs against the Rockies this year, but the Giants are just 4-7 in the season series.