ST. LOUIS -- This is the third of a seven-part Around the Horn series that will take a position-by-position look at the Cardinals' projected starters and other options heading into Spring Training. Up next: middle infielders.

The Cardinals entered the offseason with limited question marks, the result of which has been minimal offseason activities. To date, the Cardinals have dipped into the free-agent market just twice -- once for a reliever, the other time to snag a bench player.

With the core carrying over into 2013, the Cardinals will have few position battles to sort out in February or March. When it comes to the makeup of the team's middle infield, though, much remains fluid. Health remains particularly critical at the shortstop position, while the Cardinals continue to hope someone can distinguish himself at second base.

As a result, Spring Training will very much be used as a measure for what's to come up the middle.

Rafael Furcal is the incumbent at shortstop, and the Cardinals are optimistic that he'll begin the season as the team's everyday starter at the position. What remains uncertain, though, is how the 35-year-old's elbow responds from the rest and rehab program that followed Furcal's season-ending injury in August.

Information that the Cardinals have received from their medical staff indicates that Furcal's recovery is on point. Yet, in opting against surgery, Furcal can't be certain about how well his elbow will hold up until he resumes throwing at full effort. Spring Training will provide that test.

Given that the elbow injury was the latest in a growing list of ailments over the past few seasons, the Cardinals are expected to be more liberal in resting Furcal throughout the season. Furcal, who will give St. Louis its leadoff hitter, has averaged 98 games played per year over the past five seasons.

"I can see how it did wear on them, and there's a fine balance there," manager Mike Matheny said last month, referring to the playing time for Furcal and other veteran position players from the 2012 club. "Even as a player, you go through the same thing. You just want to play. There's a time for a manager to step in and do the right thing, which can help make an investment into the future of the season and that they'll finish as strong as they start."

Though the Cardinals have kept tabs on the middle infield market this winter, to this point, the club has not made an addition in that area. That leaves Daniel Descalso, Pete Kozma and Ryan Jackson as potential backups behind Furcal. The three -- in particular, Descalso -- also factor into the second base mix. The depth behind that bunch is not overly impressive.

Descalso has the most Major League experience of the three, though it was Kozma who shined as Furcal's replacement last September and October. The about-to-be-cast-aside first-round pick became a key piece in the Cardinals' postseason run and, therefore, earned himself the chance to reaffirm that those results were not a fluke.

The situation at second is even murkier, much as it was a year ago. Last year, the club entered Spring Training hopeful that Tyler Greene, Skip Schumaker or Descalso would emerge as the obvious choice to start at second. Greene did get the bulk of starts early, but there never was much day-to-day continuity.

Greene (traded to the Astros in August) and Schumaker (traded to the Dodgers in December) are no longer in the picture. Descalso remains, and his greatest competition for playing time at second could well end up being a player who, at this time last year, had never played the position.

Matt Carpenter, at the urging of the Cardinals, has used this offseason to become proficient at second. He played 18 innings at the position last season and hopes to be seriously considered for a starting job this spring.

"Obviously, as a competitor, I want to be in there every day," Carpenter said recently. "If this opens up a window to where that becomes a possibility, then I'm all for it. If this opens up an opportunity for just a few days a week to get at-bats, that would be great, too. But I'm preparing as if I'm going to be the guy who is going to get all the starts over there. That's how I have to look at it in order to maximize my work."

Carpenter hit .294 with a .365 on-base percentage in 114 games last season, which marked his first full year in the Majors. He appeared at five different positions.

Descalso, the Cardinals' strongest defensive option at second base, finished 2012 as Matheny's everyday choice at the position, and he'll enter Spring Training the leading candidate to retain that job. Kozma and Jackson will again be in the mix for bench spots.

Also to watch is Kolten Wong, the Cardinals' ascending first-round pick from the 2011 First-Year Player Draft. Wong spent last season shining in Double-A and will likely begin this season up a level with Memphis. Should the Cardinals' difficulties in finding a permanent answer at second base continue into the season, Wong could be in the mix for a midseason call-up.

"There are a lot of people that think he's very close," Matheny said of Wong. "I need to see a little bit more. I'm excited to watch him in Spring Training as well and give him a little bit of an extended look."