Vet, rookie shore up Giants' rotation

DENVER -- Madison Bumgarner and Tim Lincecum are the headliners in the Giants rotation.

It is the Ryan Vogelsongs and Chris Hestons, however, who are the difference makers.

The Giants have battled from a 4-10 start to the season to within 1 1/2 games of the Dodgers in the National League West, having won 20 of their last 28 games, extending their current winning streak to seven games with an 11-8 victory over the Rockies at Coors Field on Friday night.

Oh, the Giants did have their scoreless-innings streak snapped at 34, the third longest for the franchise since it moved to San Francisco in 1958, but not before Vogelsong had worked six more scoreless innings and turned the game over to the bullpen.

Saturday afternoon, in the first game of a day-night doubleheader, it is Heston who will be asked to provide the starting foundation for the Giants to add another victory to that winning streak.

It's fitting those two are getting the call in the first two games at Colorado.

They are the guys who have stepped in with the absence of starters Jake Peavy, out since April 10 with a back strain, and Matt Cain, who after undergoing elbow surgery last year was sidelined at the start of this season with a right flexor tendon strain.

Bumgarner and Lincecum are both 4-1 with a no-decision during the 20-game rebound, anchoring a rotation that since April 21 has won more games (14), had a better winning percentage (.700) and a lower ERA (3.15) than any other team in the National League.

Tim Hudson has been the dependable back-of-the-rotation guy the Giants expected all along.

It, however, is Vogelsong and Heston who have stepped in to fill the voids created by the absence of Peavy and Cain.

"That's what it takes, depth," manager Bruce Bochy said. "It's big to have guys step up when someone goes down."

It's the Giants' way.

Think about it.

They seem to have the ability to turn to a non-descript player in a time of need and watch that player take advantage of that opportunity. There's not the flash of the Dodgers or the Yankees. It is, however, a formula successful enough that they have won three of the last five World Series, a stretch of success no NL team has enjoyed since the St. Louis Cardinals were World Series champions in 1942, 1944 and 1946.

Video: SF@COL: Vogelsong strikes out five over six innings

Vogelsong was 12-19 with a 4.62 ERA the past two seasons, battling injuries and inconsistencies, and as a free agent last winter was reported to have been close to signing with the Houston Astros, only to wind up back with the Giants, who told him he'd be a long reliever and insurance policy in case a starter got hurt.

"We were lucky to sign him," said Bochy. "I think he even underwent a physical in Houston, but we stayed in touch all along. He knew we wanted him."

No problem. It was the Giants who welcomed him back to the big leagues in 2011, after a three-year stint in Japan and the Minors, and if they were willing to stick with him despite the past two seasons of struggle, he was willing to fill whatever role they had.

And he has done just that, the Giants winning five of the six starts he has made since April 21, while he has been 3-1 with a 2.86 ERA. He's allowed just three runs in 25 2/3 innings his last four starts.

"He's really done a nice job," Bochy said. "He's found that fountain of youth."

Heston, a 12th-round Draft choice in 2009, had spent the past two seasons at Triple-A Fresno, getting to make his big league debut with three appearances and 5 1/3 innings last September. He was given his chance in place of Cain in the season-opening rotation and has responded by going 3-3 with a 3.72 ERA in eight starts. The Giants won both of his no-decisions.

"Chris has been solid, filling in for Matt Cain," Bochy said. "It's been a nice lift for us."

Video: SF@HOU: Heston fans 10, pitches a complete game

Vogelsong and Heston are creating a depth that will force interesting decisions before long.

Peavy made his first start on a Minor League rehab assignment with Class A Advanced San Jose on Friday night, allowing one hit and a walk while striking out four in 3 1/3 innings. He's expected to start for Triple-A Sacramento on Wednesday, with a potential return to the big league roster in mid-June.

Cain, meanwhile, threw a bullpen session that featured offspeed pitches Friday, and if he feels strong Saturday, he will face hitters in a batting-practice session Tuesday. The hope is he could be ready in July.

Until then, Vogelsong and Heston are doing what the Giants need to put the team in position to challenge the Dodgers in the NL West.