As I write this, the St. Louis Cardinals are 44–46, two games below .500, 6.5 games back of the NL Central-leading Brewers and 1.0 games back of the Cubs. That’s not a great record, admittedly, and it might be easy to look at the Cardinals and think they should think about trading some players away and building for the future.

But John Mozeliak, Cardinals President of Baseball Operations, has never presided over a trade deadline of sales, and 2017’s looks unlikely to be the first. They’ve been connected to Giancarlo Stanton, among others, and all indications are that they see themselves as legitimate playoff contenders, and are taking steps to improve for a late-summer push.

Matt Carpenter's strange first half The St. Louis Cardinals' infielder is having one of his worst seasons as a major leaguer. Is it luck, changes in approach, or both?

And they’re absolutely right to do so. I wrote a couple weeks ago about how the Royals should go for it, because playing meaningful, exciting games in August and September is good and valuable, even if the team ends up short of a playoff appearance. At the time, Kansas City had a 16.6 percent chance of making the Wild Card game or winning the AL Central, so my threshold for a team being a buyer is clearly pretty low, just on principle alone. The Cardinals, who FanGraphs gives a 28.7 percent shot at the postseason in some form, already are in a better position than the Royals. But there’s one important reason that St. Louis, more than other teams in the same range of playoff odds, should go for it in 2017: the Chicago Cubs.

The Cubs have struggled mightily in 2017, failing to string together any sustained success and hovering right around the .500 mark for almost the entire season. Every indication is that they’re still a very talented team; FanGraphs projects them for a .577 winning percentage in the rest of 2017, tied with the Astros and behind only the Dodgers. The result is that FanGraphs gives the Cubs a 77.8 percent chance of making the playoffs, despite the lead the Brewers currently hold in the central.

But the Cubs roster is not constructed just to be better than they have been in the second half of 2017. The terror of the Cubs is that they are built to last long, long beyond the current season. As I wrote in February, the Cubs are unique not because of their high-end, but because of their youth. Most of their ultra-talented players are also extremely young, and even the reinforcement they acquired for 2017 is José Quintana, signed for another three seasons after the present one.

The Cubs are almost certainly going to be good for the rest of 2017. But it’s 2018 and beyond, when they can combine this super-young (and improving) roster with whatever free agent(s) they want to spend their World Series cash on (Bryce Harper? Yu Davish?), that they’ll look like a dynasty in the making.

So not only do the Cardinals (and the Brewers) face a surprising opportunity this season, thanks to the Cubs’ swoon, it’s possible it’ll be the last such opportunity they face in a long, long time. The NL Central looks like it’s about to get very difficult for non-Chicago teams. And so while the Cardinals might not ordinarily want to go all-in on overtaking both the Cubs and the Brewers over the next two months, waiting for a better opportunity doesn’t sound like a viable alternative.

I’m not suggesting that the Cardinals totally mortgage their future in pursuit of the present. They’ve managed to buck the traditional win curve over the last several years, and despite enjoying a number of winning and successful seasons, they have a solid core of young players, and not too many aging and departing veterans. But the best opportunity to use that core at any point in the next five years might be happening right now. They shouldn’t shy away from it; if they do, the juggernaut Cubs might keep them out in the cold for a long, long while in 2018 and beyond.