The Pirates' road to the playoffs in 2017 is no easy ride. The NL Central houses the heavyweight-champion Cubs and the chronically relevant Cardinals, so the margins for error are compressed, even with a pair of wild-card berths for the claiming.

It follows, then, that Pittsburgh, coming off a 2016 campaign that saw it finish five games below .500 and get outscored by the opposition, needs a number of things to break its way in 2017.

You could make a list.

Andrew McCutchen needs to rebound to something close to his 2012-15 MVP-caliber peak.

Jung Ho Kang needs to better himself off the field.

Josh Harrison needs to produce at a higher level.

Josh Bell must continue adapting to the highest level.

The bullpen must replace the contributions of Mark Melancon, who was traded way to the Nationals last season and signed with the Giants not so long ago.

Moreover, the Pirates need more from their rotation, wherein a number of unknown quantities reside.

In 2016, Pittsburgh ranked 11th in the NL in rotation ERA and 10th in FIP, or Fielding Independent Pitching, which is scaled to look like ERA but reflects just those outcomes that have nothing to do with fielding -- i.e., strikeouts, walks and home runs allowed. As well, Pirates starters ranked just 13th in the NL in innings. They also sent 14 different starting pitchers to the mound in 2016, which obviously isn't an indicator of stability.

All of this is not what we've come to expect from staffs instructed by Ray Searage, but it's a reminder that pitching coaches aren't alchemists. Suffice it to say, if the Pirates are going to get back to the postseason in 2017, then the rotation will have to make significant gains.

Since the 2016 non-waiver trade deadline, the Pirates have dealt Francisco Liriano to the Blue Jays, sent Jon Niese back to the Mets and allowed Ryan Vogelsong to depart via free agency, among other departures. On other side of the things, the Pirates this offseason most notably re-upped with Ivan Nova (more on him in a moment).

So given what's in place, what needs to happen, rotation-wise, for the Pirates to challenge in the NL Central? Consider what follows to be a non-exhaustive list of questions that need to be answered in the affirmative ...

1. Can Gerrit Cole stay healthy?

Last season, the Pirates' ace was limited to 21 starts and 116 innings. That's because Cole had two separate stints on the DL -- one for a triceps strain and another due to elbow inflammation. In 2014, Cole dealt with shoulder and lat issues, so he's no stranger to health concerns.

Cole has proved he can be a front-line guy in terms of both run prevention and volume: In 2015, he topped 200 innings, pitched to an ERA+ of 149 and finished fourth in the NL Cy Young balloting. That's the guy the 2017 Pirates need back.

Unfortunately, Cole has provided such value only once in his three full seasons as a rotation fixture. What's also troubling is that nothing predicts future injuries quite like injuries in the season prior. The state of Cole's elbow will thus be worth monitoring closely in 2017. Someone given to bad puns might say the Pirates' hopes in 2017 hinge on Cole's hinge. You won't hear such thing in this space, though.

2. Can Ivan Nova sustain his improvements?

Please regard the following performance-by-team splits on the part of Mr. Nova ...

Team Games Starts ERA

K/BB ratio Yankees 131 118 4.41 2.28 Pirates 11 11 3.06 17.33

The improvements? Substantial and broad-based. The sample size in Pittsburgh? Vanishingly small.

The Bucs acquired Nova from the Yankees in an Aug. 1 trade and he took off on their watch. Obviously, when a veteran hurler makes strides under Searage, we're inclined to thank those gains are sticky and sustainable.

Are they, though? With the Pirates, Nova didn't change his pitch mix to any meaningful extent and there don't seem to be any mechanical changes that leap out to the untrained eye.

What Nova did do is pound the zone. With the Yankees last season, Nova walked 5.9 percent of the batters he faced, which is a quality figure. With the Pirates, however, he walked just 1.1 percent of opposing hitters, which is an absurdly low figure. In matters related, Nova with the Yankees last season threw pitches in the strike zone 43.1 percent of the time, and with the Pirates that figure increased to 51.2 percent.

Obviously, adjustments that elude easy detection may have helped him exhibit improved command. What is probably also at work is that Nova is out of the DH league and into a home ballpark that's far more forgiving than Yankee Stadium or, really, pretty much any AL East venue.

It's also worth noting that six of his 11 starts with Pittsburgh came against the Reds, Brewers and Phillies -- three of the worst offenses in all of baseball last season. More than anything, more accommodating matchups and increased confidence that he can throw the pitch he wants without dark thoughts of the short Yankee Stadium right field porch might be driving Nova's improvement. Potentially, that's good news for the Pirates.

Still, it's worth calling attention to that sample size once again and pointing out that regression is always a possibility. The Pirates, though, have bet three years and $26 million that Nova can be an asset.

3. Can Jameson Taillon contribute right away?

4. Can Tyler Glasnow do the same?

Taillon and Glasnow are the top young arms in the Pirates organization and the big-league club will very likely need significant contributions from them in 2017.

Taillon, who figures to open the season in the rotation, looked quite strong in 18 starts for the Pirates last season. Over that span, he pitched to a 3.38 ERA with only one unearned run allowed, and he registered five times as many strikeouts as walks. He also backed it up with a groundball percentage north of 50.

Taillon is going into his age-25 season, so he's certainly at an age that lends itself to near-peak performance. It's also worth noting that Taillon is a former No. 2 overall pick who was a regular on top-100 prospect lists as he climbed the rungs. That is to say, he has the pedigree to keep doing what he did in 2016. The Pirates could certainly use another arm that profiles as a front-line or mid-rotation guy, and Taillon could be just that.

Glasnow might need a few Triple-A starts before he bumps Chad Kuhl or Steven Brault. He boasts swing-and-miss stuff with his mid-90s fastball and plus curve, but control problems have been too much with him. Better harnessed stuff and more confidence in his changeup will be in order.

Elsewhere, there's the makings of some depth, what with Drew Hutchison, Juan Nicasio, Nick Kingham and others in the fold. Using that depth, while ideally not having to use 14 different starters once again, will be essential.

However, four names will determine whether the Pirates in 2017 have a playoff-worthy rotation: Cole, Nova, Taillon and Glasnow.