Rotation may be among best, but depth an issue

This is the fifth of a seven-part Around the Horn series that will take a position-by-position look at the Cardinals' projected starters and backup options heading into next season. Previous installments examined the catchers, corner infielders, middle infielders and outfielders. Up today: Rotation.

ST. LOUIS -- Though returning a potential stalwart starting staff, the Cardinals still enter 2015 peppered with questions -- and for some, concerns -- about the depth of those rotation options.

Organization depth has been paramount in the Cards' recent run of four consecutive postseason berths. It helped the club stave off regression when Adam Wainwright, Chris Carpenter, Jaime Garcia, Michael Wacha and others were lost for extended periods of time. This club, however, may lack that luxury.

The need to pursue more offense this winter cost St. Louis one established starting pitcher (Shelby Miller) and another (Tyrell Jenkins) on the rise. The Cardinals later explored adding a front-line starting pitcher through the free agent or trade markets before eventually opting to stand pat.

That's because they are bullish on the health of their returning starters and the upside of a pair of young arms. But is that sufficient coverage?

Wainwright, a third-place finisher in the National League Cy Young Award voting after a 20-win 2014, returns to anchor the staff. Behind him sits Lance Lynn, whose recent three-year extension rewarded the right-hander for emerging as a rotation workhouse. John Lackey adds another veteran presence, while Wacha hopes to prove himself as more than an October wunderkind.

Video: Martinez set to join Cards' starting rotation in 2015

Carlos Martinez assumes pole position for the final rotation opening, though Marco Gonzales and a healthy Garcia could give strong pursuit of that same job. For Martinez, this will be his second straight spring immersed in a starting competition. Last year, he lost out to Joe Kelly, who was traded to the Red Sox in the Lackey deal.

"I feel mentally, emotionally really good that I've had that chance to work real hard there and bring that to Spring Training," said Martinez, who recently wrapped up a winter ball stint in the Dominican Republic. "I feel really good about it."

While high in their hopes for Martinez and Gonzales, the Cardinals must also be realistic. The two have made a combined 18 Major League starts, and neither is ready to carry a full starter's load at that level for an entire season. For Martinez, efficiency issues have stalled his previous attempts to establish himself as a regular starter. He has averaged less than five innings in his eight career starts while posting a 4.86 ERA and a 1.703 WHIP.

While that fifth-starter spot brings some intrigue, health will likely determine how successful this rotation becomes. Wainwright is coming off elbow cleanup surgery and has thrown 519 2/3 innings over the last two seasons. The Cardinals are prepared to back off on the workload.

Video: Outlook: Wacha could reach elite level if healthy

Wacha returns amid questions about how his right shoulder healed following a stress reaction injury, and Garcia has to prove he can stay healthy after combining for only 16 starts the last two seasons.

"I don't want to be that guy who has to be shut down at a certain point," Wacha said. "I want to be the guy that they can lean on and trust every fifth day to go out there and get a win."