ATLANTA -- As Billy Wagner painfully limped out of the visitors' clubhouse at AT&T Park late Friday night, he conceded that he would not be able to resume his duties as the Braves' closer until the start of the World Series, if Atlanta advances that far.

The Braves will likely replace Wagner with either Takashi Saito or Jair Jurrjens on their National League Division Series roster before Game 3 begins Sunday afternoon (4:30 p.m. ET on TBS) at Turner Field.

But before making this transaction that would prohibit the Braves from placing Wagner on the NL Championship Series roster, manager Bobby Cox wants to give the club's medical staff one more chance to evaluate the 39-year-old closer's left oblique injury again Sunday.

"They're going to have the doctors look at him tomorrow and do what we can," Cox said. "I'm not so sure this round he's going to be available. Maybe next round. We've got our fingers crossed."

Wagner strained his oblique while attempting to field Edgar Renteria's leadoff bunt in the 10th inning of Friday night's 5-4 win over the Giants. Moments later, he painfully crouched on the edge of the mound holding his left hip after fielding Andres Torres' sacrifice bunt and throwing to first base.

"These guys will be fine without me," said Wagner, who has enjoyed one of the finest seasons of his stellar career. "You've got unknowns out there, and the opponents don't know any patterns. You can't gear up. With 15 years of Billy Wagner, you know what's coming. You don't know what [Craig] Kimbrel, [Jonny] Venters and [Mike] Dunn are going to do."

Lingering right shoulder discomfort prevented the Braves from placing Saito on the NLDS roster. But the 40-year-old reliever provided some signs of encouragement while completing a pain-free inning in an instructional league game at Lake Buena Vista, Fla., on Friday afternoon.

"Saito pitched yesterday and pitched well," Cox said. "He pitched an inning, struck out two, faced six batters, 18 pitches, said his arm felt fine. So we have a backup there."

If he is indeed healthy, Saito appears to be the most logical choice to replace Wagner on the NLDS roster. The Braves would likely only substitute him with Jurrjens, who has been bothered by right knee discomfort, if they suddenly didn't feel they should send Derek Lowe to the mound to start Monday's Game 4 on short rest.

Though he spent most of this season with Triple-A Gwinnett, Kimbrel has established himself as a top candidate to serve as the Braves' closer in Wagner's absence. The hard-throwing 22-year-old right-hander has recorded five strikeouts while working 2 2/3 scoreless innings during this NLDS.

Kimbrel certainly enhanced his candidacy Friday night, when he notched four strikeouts and held the Giants scoreless in the pressure-packed eighth and ninth innings after the Braves had mounted a three-run eighth to tie the game.

"That was definitely the most exciting game I've ever been a part of," said Kimbrel, who made 12 of his 21 career Major League appearances after rejoining the Atlanta roster at the end of Gwinnett's season.

Cox didn't say that he definitely plans to utilize Kimbrel as his closer in Wagner's absence. Instead, he said he could utilize a closer-by-committee that could also include Peter Moylan, Venters or Kyle Farnsworth, who recorded the final five outs in Friday's win.

"We'll mix and match the seventh, eighth and ninth innings," Cox said. "Whoever matches up those particular innings, that is who is going to be out there. We'll close with whomever. But I've always thought Moylan could close, and Farnsworth has closed in the Major Leagues. Venters, there's no reason he can't, as well as Kimbrel."