DENVER -- Giants right fielder Nate Schierholtz made his first start of the season Wednesday as the Rockies started right-hander Jeremy Guthrie with left-hander Jamie Moyer scheduled to start the series finale Thursday.

"I'd hate to get home and Nate not to have one start on this road trip," manager Bruce Bochy said. "This gives us speed in the outfield. He's had success here."

Schierholtz entered Wednesday's game 21-for-75 (.280) at Coors Field with five homers and nine RBIs.

Posey sidelined by shingles

DENVER -- Catcher Buster Posey was scratched from the starting lineup Wednesday with a case of shingles that he developed Sunday at Arizona. Manager Bruce Bochy said if this were September, Posey could play, and he pinch-hit in the eighth inning, flying out to right.

Posey said he developed blisters along his left side "that are uncomfortable." He said he first saw the blisters Sunday.

Asked if was in pain, Posey, who is on medication, said, "Yeah, just uncomfortable. The blisters are just uncomfortable."

Hector Sanchez replaced Posey in the lineup. Sanchez caught Barry Zito on Monday when Zito threw a four-hit shutout as the Giants won, 7-0, in the Rockies' home opener. Sanchez has become the personal catcher for Zito, so Posey wasn't scheduled to play Monday.

Bochy said he turned to Sanchez on Wednesday with an eye toward having Posey return to the lineup Thursday afternoon when the Giants and Rockies finish their three-game series.

"With the day game tomorrow and being on medication and still feeling quite crummy, that's why he's not playing today," Bochy said.

Shingles results from the same virus that causes chicken pox and manifests itself as a painful skin rash with blisters. Posey said he wasn't worried that any medication would affect his ability to play or that shingles would be anything that lingers and bothers him during the season.

"It's just got to play itself out," Posey said.

Posey has returned from a severe injury that ended his 2011 season May 25. He was hit in a collision at home plate and suffered three torn ligaments in his left ankle and a broken bone in his lower left leg. And now early in the 2012 season, Posey, who has played three games and gone 4-for-12 with a home run and two RBIs, has been sidelined with, of all things, shingles.

"It's just one of those things that happens," Posey said. "It could have happened some time last year, so just look at it like that."

Burrell to get first-pitch honors Tuesday

DENVER -- Former Giants outfielder Pat Burrell will throw out the ceremonial first pitch Tuesday when the Giants play the Phillies, the team Burrell played with most of his career. Burrell played with the Giants in 2010 when they won the World Series and in 2011.

When told Burrell would be doing the honors Tuesday, manager Bruce Bochy said, in disbelief, "Burrell?"

"Well, I've been wanting to get him on the mound," Bochy added. "A couple times he warmed up to be our emergency pitcher. We didn't get him in the game, and he volunteered for it. So I get a chance to take a look at it, I guess.

"It'll bring back some good memories seeing him out there. He was so instrumental in our success in 2010. I appreciate what he did on the field, in that clubhouse, the way he played."

Bumgarner's clash with Moyer to be notable

DENVER -- The matchup of two left-handers Thursday, the Giants' Madison Bumgarner vs. Jamie Moyer of the Rockies, will be an encounter between young and old with historic implications.

The difference in their ages is 26 years, 256 days. According to the Elias Sports Bureau, that is the third-largest age difference all-time between two starters and the largest since 1965.

Bumgarner will be 22 years, 255 days when he takes the mound, and Moyer 49 years, 146 days. On Sept. 25, 1965, Bill Monbouquette (29 years, 45 days) of the Red Sox opposed Satchel Paige (59 years, 80 days) of the Kansas City A's, and the difference was 30 years, 35 days, the largest all-time age difference.

Paige also was involved in the second largest age difference -- 29 years, eight days -- on Sept. 22, 1953. He was 47 when he pitched for the St. Louis Browns against 18-year-old Bob Miller of the Tigers.

Vogelsong ready for season debut vs. Bucs

DENVER -- Pitcher Ryan Vogelsong, who was an All-Star last season, will join the Giants in San Francisco and is scheduled to make his 2012 debut Sunday when he starts against the Pirates. In his second rehab start Wednesday, Vogelsong (lower back strain) pitched six innings for Triple-A Fresno at Las Vegas and allowed six hits and two runs with one walk and six strikeouts. He threw 90 pitches, 60 strikes, and was the winning pitcher in Fresno's 10-5 victory.

"He came out of that just fine," manager Bruce Bochy said. "It's all gone well with him, as well as it could. It's good to have him ready to get back in the rotation."

Crawford finds success against left-hander

DENVER -- Shortstop Brandon Crawford broke open Monday's game with a three-run double in the fifth that gave the Giants a 7-0 lead, which proved to be the final score. The left-handed-hitting Crawford, batting with one out, lined an opposite-field double into the left-field corner off left-handed reliever Matt Reynolds.

Last year, Crawford went 4-for-30 (.133) vs. left-handers with 12 strikeouts, one of which was against Reynolds. When Crawford came to bat in the fifth Monday, he was 1-for-12 overall and 1-for-2 with a strikeout against lefties.

Reynolds threw Crawford two sliders, the first a strike looking and the second a ball. Crawford took a fastball for a strike and then drove a fastball on the outer portion of the plate for his bases-clearing double.

"I knew he had struck me out before, so I wanted to keep my swing a little shorter," Crawford said. "I've gone through it enough times now that I think I know to just relax and keep it simple in that situation. It's been written that I struggled against [left-handers] last year, so to get a hit right there and kind prove people wrong, I guess, is always nice."

Zito looking ahead to next start

DENVER -- A sweet aftertaste was with Barry Zito two days after pitching his first shutout in nine years as he began preparing for his next start Saturday at home against the Pirates.

"I think I was able to enjoy it probably a little more than I have in the past," said Zito, who blanked the Rockies on four hits Monday and won, 7-0. "Definitely -- it's been nine years, so you got to soak it up. But it only goes as long as the next workday, which is today."

That included work with pitching coach Dave Righetti, who said after Zito's struggles in Spring Training he couldn't see a shutout coming at Coors Field, or anywhere for that matter, given that Zito's last shutout was April 18, 2003, against the Rangers while pitching for the A's.

The key, of course, will be whether Zito, who is 44-61 since joining the Giants in 2007 after signing a seven-year, $126 million contract, can sustain his success, something that has been hard since he joined the Giants.

"We'll find out," Righetti said, "but to dismiss [it] and say, 'Oh, it's only one game,' in a lot of ways it wasn't, because it's important for him, more than most guys at this point. He faces [criticism] every day in our little world, the Giants world, regardless if he's pitching [or not]."