Opening Day is in ten days and the Cardinals might very well have the most imposing rotation in the National League. Just being in the discussion of the best is a nice compliment given the Mets' arms, and not to mention the Nationals' staff complimented by Max Scherzer and Stephen Strasburg, the Cubs with the reigning Cy Young who doesn't happen to be Jon Lester, and the Pirates ability to turn everyone into a good pitcher.

There's a handful of starters in the NL who are probably better than Adam Wainwright - the Cardinals' ace - but this rotation from 1 to 5 is as balanced as you're likely to find. Michael Wacha has shown glimpses that he can be one of the best pitchers in baseball. And if the Cardinals' depth chart means anything on March 24, Mike Leake and Carlos Martinez are slated to be the 4 and 5, which I'll gladly take over the back end of the rotations from the other clubs in the NL.

Wacha has been an enigma of sorts, and, in my opinion, is the one likely to move the needle on whether the Cardinals will be considered to have the best rotation in the NL at year's end. That this imaginary title hinges on Wacha feels disingenuous since the rotation is so balanced as well as being less than a year removed from losing Wainwright for almost the entire season and still allowing the fewest runs in baseball. But there's going to be regression in run prevention and it would be nice to counter that with Wacha assuming the role of co-ace with Wainwright, which is a title that's been bestowed on him before.

Reasons to be optimistic

This is easy to overlook because he's been on the radar for so long but Wacha is still incredibly young. In 2015, Wacha threw 181.1 innings in what was his age-23 season. (I'm using Baseball-Reference's guide which measures players by their age on June 30, which means Wacha just slips by with his July 1 birthday.) No one younger in the NL logged as many innings. Using the Play Index, since 1988, when consistent pitch-count data began being logged, only 69 pitchers in the NL in their age-23 season or younger have thrown 180 innings or more in a single season. It's not that common and it's a list populated by a lot of good pitchers (there are lot of Madduxes, Bumgarners, and Kershaws present).

Wacha has also excelled at run prevention. A search for NL pitchers who have thrown at least 350 innings for their career before their age-24 season since 1988 returned 33 results. Wacha's 3.21 ERA and 3.48 FIP both rank ninth.

Returning to the 181.1 innings pitched in 2015, this is significant because going into the season his health was more of a question than his effectiveness. His '14 season ended with a 68-game DL stint (before being regrettably resurrected in Game 5 of the '14 NLCS) on account of a rare shoulder injury on his right side. Knowing in advance that he was going to pitch north of 180 innings in '15 would have been cause for celebration without knowing his stats. And as for those stats, the numbers weren't necessarily co-ace-like but certainly resembled that of a good pitcher.

IP K% BB% ERA FIP WAR 2015 181.1 20.1 7.6 3.38 3.87 2.3

Before Game 3 of the '15 NLDS when Wacha faced off versus Jake Arrieta - who up to that point was breaking baseball - there was a populace on my Twitter timeline looking for a silver lining in light of Wacha's rough second half of the season (more on that in a second) and often harped on the fact that he was the MVP of the '13 NLCS. Hey, we've seen this guy be dominant on this stage and there's no reason why he can't be better than this Arrieta guy. Wacha didn't have a good outing, not even close (boxscore here), but thing is one needn't go back to the '13 postseason or rely on that small of sample size to see that he had already pitched like a co-ace before.

Here's how Wacha started off 2014:

2014 IP K% BB% ERA FIP April 36.1 29.0 6.6 2.48 2.58 May 37.0 21.2 6.2 2.43 2.97

In baseball, two seasons can seem like forever ago but Wacha was dominant for those two months. He only pitched 33.2 total innings the rest of the season due to the injury and was rather ineffective in doing so - his ERA hovered near 5.00 in the second half. But for the first two months anyway, he picked up right where he left off in '13.

Reasons to be concerned

Concerns over effectiveness now likely outweigh whatever health concerns still persist (although assuming a pitcher with this sort of injury history will be healthy is never wise). Here's how Wacha started off 2015:

2015 IP K% BB% ERA FIP April 26.0 15.0 5.6 2.42 3.71 May 37.1 17.0 7.2 2.17 3.83

While he still excelled at preventing runs, these were two of his better months in 2015 and his stats mostly declined from the same two months the year before. Notably, his strikeout rate fell significantly. And his relatively low ERA for the season was aided by his strong April and May shown above - during the second half of '15 he had a 4.01 ERA and walked nearly 11% of batters. Returning to the enigma theme, Wacha's ERA from August to September/October of last year differed by 6.75.

Earlier this month, Joe Schwarz, who knows more about the intricacies of pitching than I likely ever will, addressed Wacha's loss of fastball command, and showed that this has been a persistent problem since the end of '14 in spite of his relatively low ERA. It's an issue that's on Wacha's radar. Following four-plus innings of work on Saturday, he had this to say:

"The command, it's definitely on the right track," Wacha said. "It was where I wanted it to be. The pitches are coming off the way I want them to. I definitely need a little bit more time to get them where I need them to be. But they're on the right track."

For his part, Mike Matheny agreed:

"That was good stuff," Matheny said. "I mean, he wasn't fine-tuned with the heater, but he was really close. Much better than what we've seen, and I think real close to being dialed in."

Whether that's typical spring training player and "coachspeak" is certainly a valid question, but taking it at face value, if Wacha can get his command to where it needs to be that should be a huge asset for the Cardinals' rotation. He's still very young and has already shown flashes of an ace. Watching him try to get back there will be one of the more interesting subplots in 2016.