On this final off-day of the 2012 season, the Cardinals find themselves on the brink of clinching the second wild card spot (um … yay?). They are four games ahead of the Milwaukee Brewers after their 2-1 loss to the Reds today, and 3.5 games ahead of the Dodgers, who play late tonight.

Unless the Cards suffer a Braves-like collapse in the season’s final days, it’s safe to say that the Cardinals are probably headed for a play-in showdown against Atlanta on October 5th. Aside from various roster moves, the biggest question facing Mike Matheny and pitching coach Derek Lilliquist involves setting the rotation to maximize the Cardinals’ chances.

Here is a look at some possible configurations:

Who pitches the play-in game?

The only must-win game of the season is a sudden-death confrontation with the Braves in Atlanta. The game falls on Lohse’s turn with regular rest. Also, Lohse has been one of the top starters in the National League this season, posting a 16-3 record with an incredible 2.77 ERA.

However, Lohse has been uniformly awful in postseason appearances: 0-4 record, 5.54 ERA, and averaging more than 2 home runs per nine innings. Not exactly a reassuring resume for such an important game.

Wainwright could easily be positioned to pitch the play-in game by skipping his last regular start on the final day of the season. This would give Wainwright some extra rest for the final push as well.

As we all remember, Wainwright has been incredible in postseason appearances, posting a vicious 0.51 ERA in 10 postseason games. However, only one of those appearances came in a start (in 2009), as Wainwright worked as the team’s closer in 2006. That one start was spectacular, though, as Waino pitched 8 innings and surrendered one earned run.

But how many more innings does Waino have in his surgically-repaired arm?

I must admit that the most compelling choice for the play-in game is Chris Carpenter. Despite missing most of the season with a nerve condition that could only be corrected by removing body parts, Carpenter has looked tough since his return. While his curve hasn’t been great, Carpenter has been able to spot his fastball as if no time had passed at all.

Carpenter has a terrific postseason profile (9-2 out of 15 postseason starts, with a cumulative ERA of 3.05). Granted, that doesn’t indicate how well he might do in such a high-pressure situation after a long layoff.

But let me ask you this: when everything is on the line, who do YOU want out on that mound? As he demonstrated with his relentless complete game victory over Roy Halladay last year, Carpenter is a machine. And an animal. In other words, a machinimal. He would bite the head off of a small child in the stands and paint cuss words on the walls with the child’s blood if it meant victory. When crunch time arrives, Chris Carpenter is the one man you want on the front lines, biting and clawing through the opposition.

My choice: Carpenter

Which starters remain in the rotation?

If the Cardinals get past Atlanta, they will be facing either the Reds or the Nationals in the NLDS (they eliminated the rule that says you can’t play against your own division). This five game series occurs just one day after the play-in game, so the Cardinals will need to configure their rotation in advance in order to handle either opponent.

Fortunately, the Cardinals have one of the deepest pitching staffs in the game. The surprise successes of power arms like Lance Lynn, Joe Kelly, Trevor Rosenthal, and Shelby Miller give the Cardinals maximum flexibility when configuring their playoff rotation.

Kyle Lohse, Adam Wainwright, and (most likely) Chris Carpenter will form the nucleus of the playoff rotation. The fourth and final spot would be a decision between Lynn and Jaime Garcia.

Here are the stats for Lynn versus the Reds and the Nationals:

REDS: .400 BA/.435 OBP/.600 SLG/2.25 ERA (0-0)
NATS: .545 BA/.615 OBP/.545 SLG/0.00 ERA (0-0)

Here are the stats for Garcia versus the Reds and Nationals:

REDS: .254 BA/.306 OBP/.356 SLG /2.70 ERA (6-1)
NATS: .354 BA/.409 OBP/.481 SLG /1.65 ERA (2-0)

It seems that Matheny could gain an edge by pitching Garcia against either team in the NLDS, and keeping Lynn’s powerful arm ready in the bullpen. An extra advantage could possibly be gained by pitching Garcia in one of the two home games that start the playoff round.

I created this calendar of the upcoming games to end the season, and how they might be adjusted to properly align the rotation against the teams they will be facing in the first two rounds of the playoffs (the pitchers in bold for each day would be the pitcher on regular rest, and the red names beneath are my choices):

The only viable alternative to this plan might be the one suggested by my good friend Chris. He suggests using Lance Lynn instead of Garcia. In his scenario, Carpenter pitches the play-in game, followed by Wainwright and Lohse in the two home games. Lynn would start game three on the road, followed by Carpenter and Wainwright. I must admit, I like that option as well. My only concern is Lynn’s lack of success versus these teams, but that might be offset by Garcia’s emotional tribulations.

It’s an interesting debate. How would you set up the rotation?