DENVER (AP) - Barry Zito was very good throughout last season, and even better in the postseason when he went 2-0 with a 1.69 ERA in three playoff starts.
Now, the San Francisco left-hander can only shake his head in disbelief as he struggles through this season.
In his second start since returning to the Giants' rotation, Zito allowed five runs and nine hits and struck out one in four innings of San Francisco's 6-1 loss to the Colorado Rockies on Monday night.
He is 0-8 with a 9.61 ERA on the road this season and has no answers for his troubles.
``I don't know. I don't know,'' Zito said. ``I've looked at tape of my starts in the playoffs and my starts this year. I've made more pitches this year without the results.''
Colorado's Todd Helton homered to move within three hits of 2,500. Juan Nicasio tossed six shutout innings and added an RBI single, and Charlie Blackmon also homered for the Rockies.
``He left some pitches up and he paid for them,'' San Francisco manager Bruce Bochy said of Zito (4-10). ``He had trouble with the left-handed hitters.''
Buster Posey singled and reached base for the 49th straight game against Colorado.
Zito worked out of trouble in the first inning before the Rockies got to him in the second.
Nolan Arenado led off with a bloop single - one of his three hits - and Helton crushed a 1-1 curveball into the Rockies bullpen to give Colorado a 2-0 lead. It was Helton's ninth homer of the season and the 363rd of his 17-year career.
Blackmon, who entered the game in the second inning for Dexter Fowler, led off the third with his fourth homer to give the Rockies a 3-0 lead. Colorado tacked on two more runs in the fourth on a bases-loaded single by Nicasio and a ground out by Blackmon.
``I looked the film on the home runs. Buster had his glove on the ground and that's where the pitches were,'' Zito said. ``I wanted the curveballs down and away and that's where they were.''
The Giants got a scare when right fielder Hunter Pence crashed into the wall trying to track down Michael Cuddyer's triple in the first inning. Pence lay on the warning track before San Francisco's trainers came out to tend to him. After a brief examination he stayed in the game.
``He hit the wall pretty good, I mean really good, and got the wind knocked out of him,'' Bochy said. ``Once he got his wind back he was all right.''
Pence and the Giants couldn't do much against Nicasio (8-6), who tied a season high with nine strikeouts and allowed four hits. He worked out of a bases-loaded jam in the first inning and pitched around two hit-batters before leaving after 95 pitches.
Nicasio finished his night by striking out Brandon Crawford with runners on first and third to end the sixth.
The Giants spoiled the shutout attempt on Joaquin Arias' two-out RBI double off Jeff Francis in the ninth.
NOTES: The outfield sprinklers came on briefly while the Giants were in the field in the fourth inning. ... Giants LHP Jeremy Affeldt (left groin strain) threw a bullpen session in Arizona on Monday. He next will go on a rehab assignment. ... San Francisco OF Andres Torres (left Achilles strain) flew to North Carolina to see a specialist. ... Giants RHP Yusmeiro Petit (0-0) will face Colorado RHP Chad Bettis (0-2) on Tuesday night.