The following is the second in a series at cardinals.com examining the Cardinals, unit by unit. Today: the bullpen.

ST. LOUIS -- Bullpens tend to be confounding things. Few positions see more volatility from year to year than relief pitchers, and that's certainly been true for the Cardinals.

A Cards bullpen that appeared shaky going into 2010 turned out to be very effective. But the relief corps that looked promising going into 2011 proved problematic until some major midseason upgrades. For what it's worth, the 2012 'pen looks strong for the Redbirds. But there's just no knowing until the season gets going.

This much, at least, is known: Jason Motte will be the man in the ninth inning. Outgoing manager Tony La Russa remained loath to hang the "closer" tag on Motte even when it was obvious that it was the right-hander's job. New skipper Mike Matheny has already acknowledged the obvious, that Motte will get the ball with a lead in the ninth.

Motte insists he'll pay it no mind either way.

"In this game, it doesn't matter what they call you," he said. "It's what you do out there on the field. I don't look at it any differently."

Beyond Motte, it's messy and could get messier. The Cardinals have six right-handers for what will almost certainly be five spots. And that's before the potential addition of Roy Oswalt, a move that has been heavily rumored but that the club has denied is imminent.

Mitchell Boggs, Lance Lynn, Kyle McClellan, Fernando Salas, and Eduardo Sanchez all have legitimate claims to big league jobs in front of Motte, but there just doesn't seem to be room for all of them. Most of them retain Minor League options, but it's not ideal to send a pitcher who has established that he belongs down to the Minors.

So it's possible the Cards could engineer a swap to clear some space on the roster and the payroll. McClellan, the most expensive, would be the most obvious, but general manager John Mozeliak said recently that he expects to go to camp with McClellan on the roster. That could always change, of course, but for the time being there's a numbers crunch.

"[It's a] healthy competition," Matheny said. "It has some flexibility once again to where these guys are going to have to fight for that position. With what was done in the postseason, which just completely impressed most people, with what that young bullpen was able to do, they have a lot of confidence going forward and also a lot of challenges to keep the spots that they've had."

With what's on the roster, Matheny has a slew of options. Boggs throws a hard sinker and has the ability to get ground balls. Lynn showed strikeout potential in his 2011 debut, and his history as a starter marks him as someone who could get left-handers out as well as righties. McClellan is a versatile pitcher who has started, set up and pitched more than an inning at a time in relief. Salas closed for much of 2011 and pitched long relief in the postseason. And Sanchez may have the most exciting arm of any of them, with a power fastball and a nasty slider that mark him as a potential closer in the long run.

Even more promising pitchers are knocking on the door. Hard-throwing Maikel Cleto had a rough time in some ahead-of-schedule big league cameos in 2011, but the club still loves his potential. Adam Reifer is another pitcher who could force his way into the picture as the year goes on, or in 2013. One thing that the Cardinals always seem to have is right-handed relief depth.

The left side appears set, with two nicely complementary pieces. Marc Rzepczynski, acquired last July in the trade that sent Colby Rasmus to Toronto, is a Swiss Army knife of a pitcher, able to work as a specialist, a long reliever, a setup man, or just about any other way. The club even views him as potentially a starter in the long run.

J.C. Romero, on the other hand, is a classic specialist. The 13-year veteran has averaged just over 2/3-inning per appearance over the past six seasons, and he remains a potent force against left-handed batters. His splits in recent years indicate that he should face as few righties as possible, but that shouldn't be a problem in this 'pen.

Behind them, though, there are questions. If either Rzepczynski or Romero gets hurt or doesn't work out, the Cards don't have an obvious alternative. Organizational product Sam Freeman made a solid return from elbow surgery last year and likely is ticketed for Triple-A Memphis, and he could be a candidate to step in at some point, but St. Louis is always looking for left-handed depth.