Atlanta United may very soon be Atlanta Torn Asunder. Such is the way of life in all of professional sport, but impermanence is even more the standard in the big, wide world of soccer.

Thus, the end of a stirring regular season Sunday comes with one imperative for a 21-6-6 team: With the perfect ingredients all in place, better whip up the Pillsbury Bake-Off winner of all cakes while you still can.

That means taking the Supporters' Shield for the best regular season record in MLS after Sunday's game in Toronto. And then that means being the last one standing at the close of the MLS Cup championship game Dec. 8.

If not now, there is no guarantee when.

“You want to take advantage of the opportunities when you have them,” team captain Michael Parkhurst said. “You hear about it in other sports where they’ve got this time frame. You hear about it with the Falcons – they have this time frame with Matt Ryan and Julio Jones. We feel like we’ve got a short little time frame now where we have Miguel (Almiron) and we have Josef (Martinez) and we spent the money and we’ve got the fans and we’ve got a great team. We want to take advantage of it.”

Some players shy away from framing winning a championship as a necessity. Parkhurst isn’t one of them.

“Just because it started this way doesn’t mean Atlanta United will always be the best team in MLS. We want to make sure while we have that opportunity now, we take advantage of it and win,” he said.

Atlanta United will wrap up the regular season at Toronto

They've all been put on notice. Just this week, manager Gerardo Martino made official his decision to leave the club at season's end. One of the founding fathers of United – the man responsible for setting the tempo for a team that in just two seasons has produced the league's catchiest beat – will reportedly join Mexico's national team as manager.

“Win one for Tata” is not the worst cry that could arise in advance of the race to the MLS Cup.

Winning, said Atlanta United goalkeeper Brad Guzan, would be a nice gesture, “not only to show appreciation to (Martino), but also to show appreciation for the city, for the fans, for the club.”

“A lot of hard work has gone into the last two years and nothing changes from what we’re trying to accomplish. We know (Martino’s) fully committed and on our side for the next month and a half or whatever. Afterward, you shake hands and wish each other well and go your separate ways,” Guzan said.

The manager himself does not subscribe to the now-or-never point of view.

Before his leaving was made official, Martino said, “It’s not to say that if we don’t win this year then Atlanta is not going to win, because this club has ambitions and goals to try to be competing for championships season after season.

“And if we do win the championship this season, then next year the ambition and the expectations will still be the same – to try to win the championship.”

Just with something else leading them. And who knows about the future of the team’s two leading goal-scorers, Martinez and Almiron?

Martino’s imminent departure underscores just one of the aspects of MLS that exaggerate the ephemeral nature of rosters and team leadership. This is not a last-stop league, not an ultimate destination.

Players and managers in Major League Baseball may move between teams in the same league, but their ambitions never can take them somewhere overseas with a better class of ball. But on the global scale, there are bigger, more prestigious challenges than MLS. There is a world worth of reasons to pack up and move out there.

It’s not just MLS players who may aspire to test themselves on the world market. The teams, too, have cause to shop their best players as commodities that can return a healthy profit in the form of transfer fees. It is a speculative venture unlike any in the other major American professional sports.

Case in point: The Vancouver Whitecaps this season were paid a record MLS transfer fee of reportedly $13.5 million (perhaps as high as $22 million, with incentives) by Germany’s most prestigious club, Bayern Munich, for 17-year-old Alphonso Davies. The Whitecaps paid Davies $72,500 this season.

That Atlanta United was going to be very good this season was nearly a given, returning practically everyone from what was only the third expansion MLS team to make the playoffs. “We knew we were going to be better than last year, at least on paper. We just had to bring it on the field. I think we’ve done that so far,” midfielder Julian Gressel said.

But success breeds attention, and attention breeds interest. The dynamic 24-year-old Almiron has made it clear he wants to play in Europe next year. A record goal-scorer like the 25-year-old Martinez is certain to chum the waters, too.

All of which is exactly the scenario Atlanta United was hoping to create with its strategy of bringing in so much raw young talent – mainly from South America – rather than rely on more familiar names past their prime (the old MLS model). Today’s transfer fee ideally is tomorrow’s investment in the next generation. In this game, such fees, and with them players, flow in and out like the tide.

Perhaps, as Guzan said, it does no one any good to think about this spin cycle of change. It can be a little dizzying.

“It happens in this league. Players come and go. Managers come and go,” he said.

“You can’t be thinking in a year from now, two years from now, five years from now. You’re always trying to think in the moment and be in the moment.”

So, the advice at this moment for Atlanta United: Get it while you can. And for the fans: Enjoy it while you may.