TAMPA — The Mets’ fifth starter battle between Steven Matz and Michael Wacha could result in one of them winning, both of them kind of winning or neither of them winning.

For now the Mets’ public stance is that they will not announce pitching roles until later in spring. Why do it now when injury or performance in the next few weeks could make decisions for them?

But among the options they are internally discussing, The Post has learned, is using that fifth spot to match up best against each specific opponent. The determination would be whether the lefty Matz or the righty Wacha matches up best to start. Or the Mets would use Robert Gsellman or maybe even Seth Lugo as a one- or two-inning opener should the Mets conclude that is the best course. In that situation the opener would be followed by Matz or Wacha for bulk innings.

With three off days in the first 12 days of a season that begins March 26, the Mets will need to pick who goes in the fifth spot just once before April 11. After that?

The Mets are hoping they are in position to have to decide because it would indicate the full health of their key pitchers and success in spring training.

One of the first signs that they were at least seriously considering an untraditional pattern for their fifth starter was how the Mets structured Wacha’s contract. He signed with eyes on starting. But the pact awards Wacha $250,000 each for 40, 45, 50 and 55 relief appearances. More pertinent, Wacha also accumulates one point for every relief appearance of three innings or more. At seven different point totals beginning with 10 and ending at 30, Wacha would receive $500,000 each.

And why would Wacha pitch three innings in relief so frequently? Because the Mets presented that he could be the bulk-inning pitcher after an opener.

“We are not defining roles on the roster or bullpen until we get deeper into camp and we have further clarity on the roles,” GM Brodie Van Wagenen said by phone.

Asked about the plan by The Post’s Mike Puma, Matz said, “I haven’t heard it yet so I am not going to comment on it. Until they tell me that then I guess I will form an opinion on it. … I asked them the other day in the meeting, ‘Am I possibly going to be a reliever?’ They said right now you’re a starter. We have got six starters, this is what we have got and we’ll go from there.’ ”

Van Wagenen realizes not to commit too early to a strategy that needs full or close to full health. So in the unlikely event the Mets have that, how would this look?

Jacob deGrom, Noah Syndergaard, Marcus Stroman and Rick Porcello will be the first four starters (the Mets see Porcello as a durable starter with little relief value). The first time they would need a fifth starter is April 1 and let’s assume Sidd Finch is not available that day. The opponent is the Phillies. The Mets could start Matz with the idea of trying to neutralize lefties Bryce Harper and Didi Gregorius (who actually have good numbers against him) or go with Wacha, feeling it is more important to create righty vs. righty matchups with Rhys Hoskins, Andrew McCutchen, J.T. Realmuto and Jean Segura.

Or the Mets could open with Gsellman backed by Matz or Wacha. Matz often battles high pitch counts that shorten his outings, so if he is going to give five innings, the Mets could try to have him avoid the top of the lineup once by using an opener. Wacha went beyond five innings in just eight of 24 starts last year.

The intriguing opener would be Lugo, who has stated a preference to start, just not like this. Lugo, though, would give the Mets the best chance to author two dominant innings from the outset. This only works, though, if Dellin Betances, Edwin Diaz, Jeurys Familia and Justin Wilson are healthy and performing at a high level to liberate Lugo from being needed for the late innings.

Whoever would be used in that fifth spot — starter or opener — would also be beholden to what the Mets needed in the days prior. For example, if the late-inning relievers had been heavily used, Lugo would not be a candidate to open. If an extra-inning game necessitated Matz or Wacha for length, the one used would not start in the fifth slot that time around.

Implementing a scheme like this is easier in the imagination and on paper than in a reality that will include short starts, extra innings, injuries and rainouts that will force audibles.

The Mets believe, though, that the depth and versatility will provide options and keep them from feeling shorthanded. The key being health permitting. That is why they are just plotting alternatives for now as they, for example, see if Betances continues to move well after a partially ruptured Achilles tendon. And they are also monitoring Familia’s splitter to see if it keeps looking as good as it has early in camp and that he can return to getting big late outs to free others for different roles. They are staying mum about who will do what while internally keeping an open mind about the fifth starter spot.