Sox outfielder Bobby Kielty, during batting practice yesterday in Boston, has had great success hitting against Cleveland’s top pitcher, C.C. Sabathia.

The Providence Journal / Bob Thayer

BOSTON — As he walks through the clubhouse, Bobby Kielty is as anonymous a player as you’ll find on the Boston Red Sox.

The only reason the journeyman outfielder stands out is his hair, a bright red, though it is closely cropped.

But if past performances are any indication, tomorrow night, Kielty could become a household name in New England, if not all around the country.

That’s because, in baseball players’ parlance, Bobby Kielty “owns” C.C. Sabathia, the flame-throwing left-hander the Cleveland Indians will be starting in Game One of the American League Championship Series at Fenway Park.

Kielty, a switch hitter, has gone 9-for-29 against Sabathia. That computes to a .310 batting average. And while that’s impressive enough, it is Kielty’s power numbers against the mammoth 6-foot-7, 290-pound Sabathia that stand out even more.

In those 29 at-bats, Kielty has bashed 2 homers and 4 doubles, knocking in 7 runs. His slugging percentage in the personal battle is a whopping .655. To put that number in context, the Yankees’ Alex Rodriguez, who posted league-leading totals of 54 homers and 156 RBI this year, also led the A.L. in slugging percentage — .645. Kielty, who had only 52 at-bats after joining Boston on Aug. 18, has had so much success against Sabathia, that it’s clear Red Sox manager Terry Francona is at least thinking about starting him in right field tomorrow night, replacing J.D. Drew, a left-handed hitter who is 0-for-3 with 3 strikeouts against Sabathia, a Cy Young candidate who went 19-7 with a 3.21 ERA this year.

Not that Francona was ready to make that announcement yesterday morning in a news briefing.

“We’re going to have a meeting [later in the day]. We haven’t talked to anybody about our lineup or our roster,” said Francona before the Sox’ workout. “Bobby certainly has some success against Sabathia. What we do . . . I’d rather wait [to make any announcements] until after I talk to the players.”

Kielty, who turned 31 two months ago, seemed prepared and eager for a starting spot in the ALCS opener.

“I’m excited,” said Kielty, who has gone hitless in nine previous postseason at-bats with Minnesota (0-for-7 in 2002) and Oakland (0-for-2 in 2006).

“I’ve been to the playoffs before but I’ve never started. It has been more of a pinch-hitting role. But this seems to be a very good matchup for me. I have had success against C.C. I have a lot of at-bats against him from when I was with Minnesota (a Central Division rival of the Indians). I see the ball well out of his hand,” said Kielty, a 6-foot-1, 225-pounder.

Kielty, though, is well aware of his role with the Red Sox. He knew that, after being designated for assignment by the Athletics on July 8, if he found another job in the big leagues it would be on a contender looking for a veteran presence with the ability to come off the bench.

That’s why he signed with the Sox, who assigned him to Pawtucket, where he batted .237 with 2 homers and 5 RBI in 10 games before being promoted to Boston. Kielty knows what is expected of him and how to go about maximizing his effectiveness.

“As a role player, I’m used to being up in big situations. I prepare myself each day to be ready to go out there and do some damage,” said Kielty of the late-inning pinch-hitting appearances that tend to crop up for players on the bench.

That’s not always an easy role for a big-leaguer to adapt to, acknowledged Francona.

“Everybody’s different, how they handle things,” said Francona, who was a role player for most of his big-league career. “Whether you call it a role player, backup player, a guy who doesn’t play every day, however you term it, the way you handle frustration is probably one of the most important things [about the job] because there is so much frustration.

“When you don’t play every day and you take an 0-fer, you have to sit on that [hitless day] for a long time. Being able to handle that and then not have an adverse effect on the ball club can be pretty important. I think our guys not only handle it, but have a positive impact on our ball club, which I think is somewhat rare. It’s hard to do,” said Francona.

Since arriving in Boston, Kielty, who batted .231 with 9 RBI in his 52 at-bats for the Sox, has been a quiet person in the clubhouse. Francona tries to give his bench players playing time to keep them as fresh as possible so when they are called upon to produce, they at least have had some recent, if sparing, action. Otherwise, says Francona, it’s not fair to expect too much from a reserve player who gets thrown into a pressure situation.

But that’s where Kielty is likely to find himself tomorrow night, in the national-media spotlight in Game One of the ALCS, standing in the batter’s box with Sabathia standing on the pitching rubber, the ball in his hand, ready to sizzle a high-90s fastball or a sharp-breaking slider to the plate. There is no place Kielty would rather be — in the postseason, and facing a pitcher he has “owned,” a situation that very likely will come to pass.

“Where I came from [Oakland, which finished with a 76-86 record] to being on a team with a chance to get to the World Series is great,” said Kielty. “And when you’re facing a pitcher you’ve had success against, it’s great for your confidence.”

skrasner@projo.com