#MLBFrontOffice: If I were managing a major league roster ...

Chris Young and Chris Colabello are two players who weren't key considered key players on their teams early in the season, but ended up becoming just that. AP Photo, USA TODAY Sports

After years of tracking how MLB general managers utilize and tweak their 25-man big league rosters as the founder of MLBDepthCharts.com and now RosterResource.com, Jason Martinez now gets the opportunity to be his own GM and lay out some of what he has learned. He passes along some of the tools of the trade and how HE would manage a big league roster throughout the course of a season.

One of the most underrated aspects of finishing MLB's 162-game marathon with a playoff berth is the contribution of those players who didn't start the season in a significant role and, in many cases, weren't even expected to reach the majors.

Once spring training arrives and in the weeks that follow, we will be reminded again and again that while baseball isn't a true contact or collision sport, injuries do happen. Even by mid-March, several players will be questionable for Opening Day with muscle strains, and many of them are placed on the disabled list for the first few weeks of the season. Others won't be so lucky. The Tommy John surgery epidemic, which normally knocks a pitcher out of action anywhere from 12-18 months, is sure to continue to wreak havoc on major league pitching staffs. By the end of April 2015, a dozen MLB players (11 pitchers, 1 catcher) who had been seemingly healthy heading into spring training were recovering from season-ending Tommy John surgery. Several others would join them by season's end.

So why do we scratch our heads in disbelief when a team like the Dodgers fills out their roster with pitching to the point that a proven MLB starting pitcher like Alex Wood could possibly begin the season at Triple-A?

Well, because we tend to think of an MLB roster as having just 25 players, with room for only five starting pitchers. The fact that at least one of those starting pitchers will probably miss time with an injury and at least one other will pitch poorly enough to be removed from the rotation can get lost on us. But it's rare for a team to go through a season in which both of those scenarios do not occur.

Let's look at 2015 as an example:

How many teams used only five starting pitchers? None.

How about six starting pitchers? None.

Seven? If only a team could be that lucky; again the answer is zero.

Two teams, the Pittsburgh Pirates and Baltimore Orioles, used "only" eight starting pitchers. The Los Angeles Dodgers topped the list with 16, while the Cincinnati Reds and Philadelphia Phillies each used 14 different starting pitchers.

On average, an MLB team used 11 different starting pitchers during the regular season in 2015. While the bottom six of that group accounted for only 22 percent of a team's starts as opposed to 78 percent for the top five, that's still 36 starts made by an assortment of pitchers that most people didn't expect to see at all.

And how many relievers does it take to get through the season? It's hard enough to find seven reliable ones, but try finding three times that amount. That's right, on average, teams used 21 different relief pitchers during the 2015 season, with the bottom 14 accounting for 135 relief appearances.

While losing position players for more than a 15- to 30-day period is much less likely than it is for pitchers, teams still used an average of 23 position players in 2015, with the bottom 10 players logging an average of 554 at-bats. So we're talking about many players each season who couldn't crack a starting lineup at Triple-A to begin the season reaching the major league club at some point.

I present these averages (36 starts, 135 relief appearances and 554 at-bats) only to give you a general idea of how much a team's "depth" can be expected to cover. It could be much more or less depending on injuries and the level of impact an injured or underperforming player was expected to have on a team. So with that in mind, here are my keys to building a team that can endure all of the bumps, bruises, twists and turns of a major league season:

1. Always have an innings-eater -- or three