It’s a perfect storm of ingredients: In a very successful first season at Allianz Field, Minnesota United is set to host a Major League Soccer playoff game Sunday against the L.A. Galaxy.

But a day earlier, St. Thomas and St. John’s are playing the first football game on that same field, which could wreak havoc on it.

Oh, and did we mention the grass playing surface has been completely replaced in the last few weeks after problems during the regular season — including complaints from Galaxy players when they played here earlier in the year.

How did we get here? Is this really a big deal? Let’s sort through it:

*United could have avoided at least part of the problem with the playing surface by not scheduling a football game in the first season at Allianz Field.

That’s second-guessing in hindsight, and a late change in the MLS playoff format (combined with the Loons earning a home game) are the main culprits in the dual-sport weekend dilemma.

Planning for the football rivalry game was no doubt a long process. It’s worth pointing out, though, that the St. Thomas/St. John’s game at Allianz wasn’t officially announced until early December of 2018, at which time media reports about the MLS format change had already surfaced.

But playing different sports in stadiums has become a money-maker and a novelty. TCF Bank Stadium has had hockey. Target Field has had football. A college football game at Allianz is just another sign of the times.

*The consternation over the playing surface and the reaction of some Loons fans aghast that football is sharing a field with the soccer team is most certainly another sign of the times.

You don’t have to be that old to remember a time when pro teams in different sports routinely shared grass fields.

In fact, the NFL’s Raiders and MLB’s A’s still did it this season in Oakland (for the last time, alas, with the Raiders set to move to Las Vegas and deny us the image of September football games on dirt infields).

And New York City FC, the top seed in the MLS Eastern Conference, shares a home field with MLB’s Yankees. NYCFC has a bye to the conference semifinals next week, and if the Yankees are still alive in the postseason the soccer playoff game could be moved to Citi Field, home of the Mets. But they’ve managed to play soccer and baseball at Yankee Stadium for the last five overlapping regular seasons.

*Those with a bent toward history should consider how things played out on the Twin Cities sports scene in 1976:

The Kicks hosted the North American Soccer League conference semifinals and conference title games on Aug. 21 and 25, respectively.

The Twins had a home stand that lasted until Aug. 19 and then returned home for a game Aug. 30.

The Vikings had preseason home games on Aug. 22 and 28.

All of that happened on the grass of Metropolitan Stadium in Bloomington. I don’t recall complaints about the field (to be fair, I wasn’t born yet), but all the games were played so I can only assume the field held up.

A Division III football game and one MLS playoff game? That shouldn’t be a problem and wouldn’t have raised an eyebrow a generation ago.

*The stakes are higher in sports nowadays, of course. Athletes make millions. Team owners are worth billions. Keeping fields in pristine condition is the expectation, and any deviation is upsetting.

Back in April, L.A. Galaxy star Zlatan Ibrahimovic took a divot out of the soft new Allianz turf and then chucked it back in pieces toward the hole he created. Galaxy goalkeeper David Bingham called the condition of the field “terrible.”

United is trying to fix that before this weekend. Let’s hope any controversy about the playing surface fades into the background and is a non-issue that doesn’t distract from what could be a pretty special two days in St. Paul.