We don't yet know who's going to survive the National League Championship Series' return to Citizens Bank Park.

We don't know if a Giants team that has already defied expectations and showed resolve all season will do so again, or if they'll crumble under the pressure of closing out a two-time reigning NL champ.

Nor do we know if the Phillies mounted enough momentum in Game 5 to do what just two other NL clubs in history have done -- overcome a 3-1 deficit in the LCS.

What we do know is that no matter who comes out of this weekend's action in possession of the pennant will enter the World Series with some questions and concerns. Because while this NLCS has certainly been captivating, with the first five games decided by a total of 12 runs, it has also exposed some weaknesses in the East and West champs.

NLDS SF-PHI
NLCS Gm 6: Sat., 7:30 p.m. ET on FOX
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• Spin Forward: Fundamentals magnified
• Why they'll win Gm 6: Giants | Phillies
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• Gm 6 starters: Sanchez | Oswalt
NLCS highlights and interviews
• NLCS coverage: Game 1 | 2 | 3 | 4 | 5

The primary problem for both the Giants and Phillies are their respective lineups, which, at their current rate of production, don't compare favorably to that of the AL champion Rangers.

While we've certainly seen some superior starting pitching this postseason and, specifically, this series, does that fully account for the fact that the Phillies are batting just .210 and the Giants just .216 in the playoffs?

Probably not. There are a few funks going on here that have led to some serious lineup tinkering from Bruce Bochy and hand-wringing from Charlie Manuel.

We'll begin with the Giants, who have been largely carried by playoff phenomenon Cody Ross. He has eight of their 25 RBIs in nine games. Take him out of the picture, and the Giants are batting .203 with one homer and eight doubles.

Fortunately for the Giants, Ross is firmly in the picture. His forearm swelled up after he was hit by a pitch from Joe Blanton in Game 4 -- an injury that might have held him out a few days if this were the regular season -- but he's not going anywhere. The Giants just have to hope he can keep feasting on inside fastballs and making adjustments now that he's the center of opponents' scouting reports. His ability to go the other way with an RBI double in Game 5 was a good sign.

But if the Giants' October run is going to end with the ultimate prize, they need more than just Ross' bat. More than anything, they need more consistency from the top of the order, where leadoff man Andres Torres has a .265 on-base percentage and No. 2 hitter Freddy Sanchez is at .256. If those two can get going -- and they both had a nice night in an otherwise forgettable Game 5 -- they'll generate more opportunities for Buster Posey, Aubrey Huff and Pat Burrell, each of whom has had some big hits this month.

Manager Bruce Bochy's lineups have become a daily source of intrigue. He keeps looking to play the hottest hands available, rotating the likes of Aaron Rowand, Edgar Renteria and Pablo Sandoval in and out of the lineup. It's not exactly standard operating procedure in the postseason. Ordinarily, the order is pretty set by this point. But Bochy's just doing what's best for his ballclub.

"Sure, you'd like ideally to have a set lineup every day," he said. "It makes life a little easier. But it's been fun. We have guys who are used to starting that lost their starting position, but they've stayed ready and they've helped out."

Though the lineup leaves a bit to be desired, the front end of the Giants' rotation -- Tim Lincecum, Matt Cain and Jonathan Sanchez -- has taken this team a long way. Still, the stakes would be raised in the World Series. Consider that over in the ALCS, five members of the Rangers and Yankees -- Robinson Cano (1.277), Nelson Cruz (1.248), Curtis Granderson (1.169), Ian Kinsler (1.039) and Josh Hamilton (.908) entered Game 6 with an OPS above .900 this postseason. Ross (1.245) was the only member of the Giants or Phillies performing at such a level.

Now, on paper, you might place this Philadelphia lineup right alongside that of the Rangers or Yanks. But as manager Charlie Manuel has carefully pointed out several times over the last week, this isn't the same Phillies offense as we were accustomed to two years ago.

Here's the telltale stat: Entering Game 6, neither Chase Utley nor Ryan Howard have an RBI in this LCS. Howard, in fact, hasn't driven in a run in his past 10 games, dating back to the last two games of the regular season. He has struck out 14 times in 28 at-bats this postseason.

"I think when we get guys on base, I think he's definitely trying too hard," Manuel said. "I think that he wants to do something, I think that he wants to feel like he's part of something."

There haven't been many big rallies to be a part of. The Phillies are 11-for-26 with runners in scoring position this postseason.

Manuel also has some concerns to overcome on his pitching staff. That he opted to use Roy Oswalt in relief in the ninth inning of Game 4 spoke to the uncertainly currently provided by right-handers Brad Lidge, Kyle Kendrick and J.C. Romero in the bullpen. And while Roy Halladay's gutsy performance through groin pain in Game 5 was impressive, there would be some obvious uncertainty over the state of that groin if the Phillies make it to the next round.

No team is perfect, of course, and postseason series ultimately come down to matchups. Though some were expecting the Phils to run away with this series, we've discovered that these two clubs match up against each other quite well. If anything, their relative weaknesses to this point have made this NLCS, which could very well be headed for a Game 7, all the more entertaining.

How well do either of these clubs match up with the Rangers? Well, obviously, they both hope to find out.