ST. LOUIS -- This is the fifth piece in a six-part Around the Horn series that is taking a position-by-position look at the Cardinals' projected starters and backup options heading into the 2019 season. After examining the position player side of things, let's move on to the starting rotation. •

ST. LOUIS -- This is the fifth piece in a six-part Around the Horn series that is taking a position-by-position look at the Cardinals' projected starters and backup options heading into the 2019 season. After examining the position player side of things, let's move on to the starting rotation.

• Around the Horn:Outfield | Middle infield | Infield corners | Catcher

Projected starters: Miles Mikolas , Carlos Martínez , Jack Flaherty , Michael Wacha , Adam Wainwright

An analysis by MLB.com recently distinguished the Cardinals' rotation as among the hardest-throwing groups in the National League. It should also be one of the deepest. The Cards are teeming with options, though the aforementioned five right-handers have the inside track to Opening Day rotation spots.

Mikolas lines up to start the opener after a breakthrough year, and Flaherty profiles as one of the most intriguing young pitchers in the game. Martinez has a ceiling higher than he's reached, while Wacha has much to prove after missing the final three months of last season. Wainwright, the veteran of the bunch, is in search of the fountain of youth after being limited to eight starts in 2018.

Other candidates/reserves: John Gant , Austin Gomber , Alex Reyes , Dakota Hudson , Daniel Ponce de Leon

This is where the organization's depth shows. Gant and Gomber were key members of the rotation in the second half last year, but they may have to wait until midseason to find a fit there again. Adding Gomber to the mix would give the Cardinals a left-handed option.

Reyes is a wild card here, as no one knows what to expect as he returns from a second surgery. The club is also determining how to balance Reyes' workload with his optimal fit. Hudson is likely to end up in the bullpen, though the organization has told him it will build him up as a starter in the spring. Ponce de Leon seems a likely candidate to open the year in Triple-A Memphis' rotation so the Cards are covered in case of injury.

Prospect to watch: Ryan Helsley

One year after president of baseball operations John Mozeliak predicted a breakout year for Helsley, Mozeliak is bullish again. Helsley didn't ascend as expected last year, largely due to injury. But he still ranks fourth on MLB Pipeline's Cardinals prospect list and remains on the cusp of being an intriguing option for the big league team. If Helsley gets called up by the Cards this year, it'd likely be for a relief role. But he'll be a starter in the Minors, where he's posted a 2.58 ERA over four professional seasons. Scouts already rave about his fastball-curveball combination.

Biggest lingering question: Does Wainwright have one more special year in him?

Expectations aren't exactly soaring for Wainwright, who hasn't been the same since an Achilles' injury stalled his 2015 season after four starts. He's been on the disabled list six times in the past four years and was ready to retire until he was encouraged by how well his arm felt in mid-to-late September. An uptick in velocity reinforced that. Wainwright signed a one-year deal in October that features a low base salary and plenty of incentives. That lessens the risk for the Cardinals and ups the potential reward for a two-time NL Cy Young Award runner-up wanting to finish his career on a high note.

Notable number: 11

That's the number of starting pitchers St. Louis used last year, tied for the highest total by any Cardinals club since 2007. The group included four rookies, who combined for 44 starts. The organization does not anticipate that sort of rookie infusion this year, mainly because those young pitchers who debuted in '18 make up the team's depth moving forward. Last season also marked the first time since '02 that the team had only one pitcher accrue at least 30 starts. The club is obviously hopeful for better stability this year.

Statcast™ note

Martinez threw a lower percentage (18.8) of four-seam fastballs in 2018 than in any other year of his career. It also marked the first time that he registered a higher percentage with two of his other pitches -- the sinker (26.3 percent) and slider (22.4 percent). That could be the result of a maturing arsenal, or perhaps the effects of pitching through injury. Regardless, when healthy, Martinez's repertoire was effective. According to Statcast™, he ranked fourth in the Majors with a barrel rate (minimum 250 pitches) of 3.9 percent and fourth with an average exit velocity against of 84.8 mph (minimum 200 plate appearances).