The Miami Marlins made the decision before they even went to spring training: They were going to carry eight relievers to go along with five starting pitchers come Opening Day, which means that 13 players on their 25-man roster will be pitchers. No ifs, ands or buts.

In my 15 years as a major league GM, most of the time I had my teams carry 11 pitchers, but we would go to 12 when needed or down to 10 if we had several days off ahead of us on the schedule. However, when I went to 12 pitchers it almost always caused huge problems for my managers, who never felt that they had enough position players to manage the offensive side of the game properly. Teams have sporadically gone to 13 pitchers in the past during the season. As Texas Rangers general manager Jon Daniels put it, "Sometimes we prefer to protect the pitching staff and can go short on the bench for a week or two at a time."

It just isn't something teams do over a full season.

So the Marlins doing so from the get-go as a matter of design represents something new in roster design, especially in the National League. Imagine the impact of a 13-man pitching staff for a field manager like Don Mattingly. Their decision has already had huge ramifications on the way the Marlins do business, both in the front office and with the field staff. And they are not alone, because several other teams are either considering going to 13 more frequently themselves, or evaluating how the Marlins’ plan will work.

"We have carried 13 pitchers as much as anybody the last couple of years," San Francisco Giants general manager Bobby Evans said. "It creates challenges relative to our bench with a backup catcher and then only three guys remaining on the bench."

The Marlins’ decision had a lot to do with their adapting to the tragic death of their ace, Jose Fernandez. They had to rebuild with an affordable rotation filled with middling or back-end starters -- not exactly a formula for contention. Their starters all have a history that says they are most effective the first two times around the lineup and usually have to depart after five or six innings. It’s a group that includes newly acquired free agent Edinson Volquez, journeyman Dan Straily (acquired in an offseason deal with the Reds), veterans Wei-Yin Chen and Tom Koehler and second-year lefty Adam Conley.

So how do you win with that? The numbers were so clear on how all of the Marlins’ drop off the third time around the lineup that the Marlins made a choice: they focused on upgrading their bullpen, both in quality and quantity. They acquired two former Red Sox relievers in Brad Ziegler and Junichi Tazawa as free agents to add to a bullpen already stocked with closer A.J. Ramos and setup relievers Kyle Barraclough and David Phelps. That depth in the pen should help improve on last year’s performance in the sixth and seventh innings, when the Marlins posted a weak 4.47 ERA and allowed 177 runs.

The Marlins’ strategy is clear. They think that if they can improve their run prevention in the sixth and seventh innings, they’ll have enough pitching to compensate for their rotation’s exits after two times through opponents’ orders and stay in contention the entire season.

However, such a decision also has wider ramifications. Mike Hill, Miami’s president of baseball operations, acknowledged to me this winter that they’d like to have a right-handed hitting first baseman to platoon with Justin Bour. Last year, Bour posted an .857 OPS against right-handed pitching with all of his 15 home runs; against left-handers he batted just .233 with no homers and a .533 OPS. Chris Carter, the National League’s co-leader in home runs last season, was available at a bargain on the free agent market this offseason and was willing to sign with the Marlins on the cheap. However, the Marlins realized if they carried 13 pitchers, they couldn’t also carry a second first baseman -- so signing Carter was out. The Marlins are so concerned with how poorly Bour hits against lefties that they’ve been working out their starting catcher J.T. Realmuto at first base, with the idea that they may have to solve this particular problem by asking other players to play several positions.

Marlins manager Don Mattingly told me that because they’re carrying 13 pitchers all of their extra players will have to be able to play multiple positions if it’s going to work. Outfielder Ichiro Suzuki can play all three outfield positions, and infielders Derek Dietrich and Miguel Rojas can play all four infield positions. Plus, you have backup catcher A.J. Ellis, and that’s your 2017 Marlins bench.

Here’s the rub: Mattingly told me he knows he’s about to become really unpopular with Marlins fans for his in-game strategy because he knows with only 12 position players he won’t be able to pinch hit for his pitcher as often as he wants. He will also have to ask pitchers to pinch hit to save position players and won’t be able to double switch every time it’s warranted. He may also be forced on occasion to play a pitcher in the field.

To help prepare for this new drastic roster infrastructure, the Marlins have spent more time than they ever have in spring training having their pitchers take extensive batting and bunting practice. Mattingly told me one of the keys is going to be that their pitchers are going to have to have an impact offensively, and they’re hoping all the extra work will mean that the Marlins get more out of their pitching staff offensively than most teams in the league.

The Fish are going to start the year with A.J. Ramos as their main closer, but like so many other teams in the sport, are going to be very flexible on how and when they use all eight of their relievers. Mattingly told me that, while there may be initial roles for each of them, he is going to follow the new trend in pen management and adjust his strategy and their usage patterns. The Marlins are open to multi-inning saves and using several different relievers closing games and in setup roles -- based on how pitchers are throwing, what part of the lineup they’ll be facing and which pitcher has the best chance of succeeding on any particular game, inning or batter.

Hill says the Marlins will also have to consider versatility in future trades for position players, call-ups and roster moves, making it extremely challenging for him to balance his rosters. He’ll also have to grade his manager on a much different scale, especially when his manager has his pitchers hit, bunt, pinch run and maybe even play in the field. This type of roster structure will really handcuff and challenge any skipper.

So the Marlins are committed to their 13-man pitching staff on Opening Day. They’re thinking outside the box and trying to find a way to win some middle innings that they haven’t won the last couple of years. It’s certainly not going to be easy, and several other NL clubs will be watching closely to see if it works to determine if they should follow suit. However, it comes with ramifications that will affect trades, call-ups, batting practice, versatility and preparation. Is it the shape of things to come? Other GMs are watching to find out.