CINCINNATI -- Should the National League Division Series need a Game 5, the Giants will turn to pitcher Matt Cain for the start.

Cain, after a long regular season and with already one postseason start in this series, is healthy and set for what will be his 34th start of the season, postseason included.

He's not the only starter in the Giants' rotation who has proved to be durable, as Tim Lincecum has made 33 starts, Madison Bumgarner 33 starts (including Game 2), Barry Zito 33 (including Game 4) and Ryan Vogelsong, who has made 32 starts, the last coming in Game 3 on Tuesday.

"Sometimes it's luck that guys can stay healthy all year," Cain said. "Sometimes you can't help little things that happen throughout the season. But I think this group of starting staff has a good repertoire of staying on a good routine."

How important is durability? Consider that the Padres, who finished 18 games back of the Giants in the NL West, used 15 different starting pitchers in 2012.

"The trainers are on top of us about staying on our routine," Cain said. "And I think we're always trying to find ways to stay healthy and that's a good thing. Guys aren't set on what they have done in the years past."

This isn't a new development for the Giants. When they won the World Series in 2010, they had four pitchers -- Cain, Lincecum, Zito and Jonathan Sanchez -- each make 33 starts during the regular season.

Romo ready for more work in Game 4

CINCINNATI -- Sergio Romo delivered a crystal-clear message when asked if he would be available in Game 4 of the National League Division Series after he tossed two scoreless innings less than 24 hours earlier.

"This is [the] playoffs," the Giants reliever said.

The Giants teetered on the brink of elimination Tuesday, when Romo completed two innings for just the second time all season. They face the same scenario Wednesday and will again Thursday should the club force a decisive Game 5.

"We fight to get here," Romo said. "This is what we push for all season long. There is no time to step back and think of myself. It's for everybody else, for everybody playing orange and black. If I get asked to pitch [Wednesday], I'm very ready and very willing."

But is he able?

"At this stage, they're all going to say 'I'm good' or 'I'm fine,'" Giants manager Bruce Bochy said. "But it's up to us to get a read on them."

The Reds opted not to extend closer Aroldis Chapman past one inning of work Tuesday, despite an electric showing that required only 15 pitches, the last one a 100-mph heater that whizzed past Pablo Sandoval's helpless lumber. Cincinnati skipper Dusty Baker cited Chapman's potential unavailability in ensuing contests as the reason he elected not to trot out the Cuban southpaw for another frame.

Bochy, on the other hand, relied on Romo and lefty Jeremy Affeldt each for a pair of innings Tuesday. Had the Giants not taken the lead in the 10th inning when Joaquin Arias reached on a two-out error, Bochy said he would have pinch-hit for Romo. Had that sequence of events unfolded, Tim Lincecum, who was warming in the bullpen, appeared ready to toe the rubber next. Instead, Bochy indicated Wednesday that the two-time NL Cy Young Award winner could provide the Giants with four or five innings of relief if necessary.

That could ease the burden on Affeldt, Romo and the rest of San Francisco's 'pen. But this is the playoffs, and as Romo suggested, the pitchers aren't going to shy away from a chance to contribute.

"That's up to [pitching coach] Dave Righetti and myself to look at them and see where they're at as far as with their stuff," Bochy said. "But at this stage, a lot of times you're running on adrenaline -- all the players are, both sides, every team in the postseason. Still, you have to keep a watchful eye on them so you don't wear them down."

Giants have good history against Reds' Leake

CINCINNATI -- The Giants went to sleep Tuesday without knowing which pitcher they would square off against the following afternoon in the National League Division Series.

When they awoke Wednesday, they learned they would be facing a right-hander in Mike Leake, against whom the hitters in manager Bruce Bochy's lineup tote a career .397 batting average (23-for-58). That includes third baseman Pablo Sandoval, who has seven hits in 10 at-bats -- including a pair of home runs -- against Leake.

The Reds named Leake their Game 4 starter late Wednesday morning. The 24-year-old assumed the roster spot of Johnny Cueto, who departed after straining his right oblique eight pitches into his Game 1 start and is now rendered ineligible for the NL Championship Series should Cincinnati advance.

The Reds could punch their ticket Wednesday if Leake can stymie a slew of hitters who have handled him well in his five career appearances against the NL West club. Of course, the Giants haven't had much success off any Cincinnati hurler during this series.

San Francisco has tallied only 12 hits through three contests. Its three base knocks in Tuesday's triumph were the fewest in a postseason victory since 2004. Leake will follow in the footsteps of Bronson Arroyo and Homer Bailey, who both spun seven innings of one-hit ball.

"[Tuesday] night, we faced a guy that came off a no-hitter and he even said he thought he had better stuff than he had in the no-hitter," Bochy said. "Our hitters said he threw well, throwing hard, hitting the spots. So I think it's more a case of the pitching we have been facing.

"We still have to find a way to score runs and really we did a pretty good job. We got a couple of walks, moved them over, and got a sac fly. That's what you have to do in a game like that. So it would be nice to get these bats going, but we have been facing great pitching."