(Sports Network) - The Cincinnati Reds are on the verge of their first National League Championship Series since 1995. Yet they are not sure who is going to pitch for them on Wednesday in Game 4 of the NLDS against the San Francisco Giants.

Johnny Cueto left Game 1 with an oblique strain that will likely keep him out the rest of this series. The injury is apparently so bad that he won't pitch in the next series, meaning the Reds may add Mike Leake to the roster, making him available to start on Wednesday.

Leake is 3-0 with a 0.77 ERA over his last three starts against the Giants and gave up one run and nine hits during a complete-game victory June 29 in San Francisco. He was 8-9 with a 4.58 ERA overall this season.

Reds' starter Homer Bailey, who was brilliant in the Game 3 loss, may have spilled the beans on Tuesday.

"We still have a lot of confidence going into tomorrow's game," Bailey said. "You know, Leake's starting tomorrow, and we have a lot of confidence in him."

Or Dusty Baker could go with Mat Latos on three days' rest. Latos came on in relief of Cueto in Game 1 and pitched well, but has been dealing with the flu.

San Francisco, meanwhile, turns to lefty Barry Zito, as it tries to once again stave off elimination. Zito enjoyed a bit of a resurgent 2012, going 15-8 with a 4.15 ERA. The Giants won each of his final 11 starts and Zito compiled a 7-0 record and 3.92 ERA over that span.

"This is more a case with rewarding Zito with how he's been pitching and the job he's done," Bochy said. "I think he's earned this."

In seven career postseason outings, Zito is 4-3 with a 3.25 ERA, but hasn't appeared in the playoffs since 2006 when he was with Oakland.

Zito has faced the Reds 12 times (11 starts) and is 3-5 with a 6.25 ERA. In six starts at Great American Ball Park, he is 0-2 with a 6.10 ERA.

"They're tough one through nine," Zito said of the Reds. "They even have some pitchers who can swing pretty well. You just can't let down even for one pitch, especially in this ballpark. You just have to live moment to moment, pitch to pitch, and not get ahead of yourself."

San Francisco kept its season alive on Tuesday, as Buster Posey scored on third baseman Scott Rolen's two-out error in the top of the 10th inning, and the Giants eked out a 2-1 win.

San Francisco entered the 10th with only one hit, a two-out single in the sixth by Marco Scutaro off Bailey, who struck out 10 and walked one over seven frames.

"Homer was lights out," Baker said. "That's the best I've seen Homer. I didn't see his no-hitter (Sept. 28 at Pittsburgh) because I was in the hospital. He's getting better and better and that's what we had hoped."

Reds reliever Jonathan Broxton (0-1) gave up back-to-back singles to Posey and Hunter Pence in the fateful 10th before fanning Brandon Belt and Xavier Nady. Posey then scored when Rolen bobbled a chopper and Joaquin Arias beat the throw to first base.

"It was a tough play," Baker said. "The ball came up on him at the last minute. This guy is one of the best. You got to give the base runner credit for hustling down the line at the same time. Most guys, they're out on that ball. That was just a series of bad events."

Ryan Hanigan's passed ball had allowed the Giants catcher to get to third.

Sergio Romo (1-0) secured the win by tossing his second straight 1-2-3 inning.

History still appears to be on the side of the Reds, who haven't lost more than two straight home games all season. Also, there have only been four teams to rally back from an 0-2 deficit and never has it happened in the NL.

Cincinnati won four of its seven regular season matchups with the Giants this past season.

The Sports Network