Every MLS team is into preseason camp now, hustling and bustling inside of domes to avoid the snowfall outside, or passing and trapping away in happier, sunnier climes.

But it’s not so sunny for all the managers in charge; a bevy of bosses start the year in the weeds, under serious pressure as the league’s 21st season commences.

In a way this makes perfect sense; there are more teams in MLS these days, so more managers feeling the crush is no surprise. Don’t forget, MLS was much smaller potatoes just 10 short years ago, with only 12 clubs operating.

So more coaches standing in hot water as 20 clubs compete is, in some ways, just simple math.

The same math says plenty of coaches are also safe and secure moving into early preseason camps. But conflict is always more interesting to talk and write about; good on the coaches who enter 2016 all “snug as bugs in rugs” and all that, but they just aren’t as engaging of a topic.

So we look with greater interest at Toronto’s Greg Vanney, Seattle’s Sigi Schmid, Real Salt Lake’s Jeff Cassar, D.C. United’s Ben Olsen, Philadelphia’s Jim Curtin, NYCFC’s Patrick Vieira, Colorado’s Pablo Mastroeni, Houston’s Owen Coyle and perhaps Orlando City’s Adrian Heath.

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That’s almost half of the MLS managerial herd – quite a gaggle feeling the squeeze of an increasingly competitive league. Heck, even venerable old ranch hand Bruce Arena might find the air getting a little stuffy inside his Carson, Calif., office.

Obviously, pressure arrives in different degrees; not all of these Charlies in Charge will fall in the “job in imminent” danger category. Certainly not Arena; the pressure is a little different there. The Galaxy had three MLS Cup titles in four years before a rickety back line and outright awful goalkeeping corrupted the 2015 bid. So the pressure at the StubHub center feels different. But there’s pressure nonetheless to regain that former, exalted status.

But in the other places, job security really is on the wane. Or worse.

Toronto FC has truly made noise in the offseason with a prudent package of additions. In Drew Moor, Steven Beitashour, Clint Irwin and Will Johnson, TFC has secured precisely what was missing from an up-and-down 2016 season: solid, veteran contributors and leaders to augment that pricey Designated Player trio, Jozy Altidore, Michael Bradley and Sebastian Giovinco. TFC had the prize fighters last year, but the undercard guys were mostly just tomato cans, especially in defense, and they were going nowhere fast without a fortified roster.

So now they have it. But that means Vanney has to produce. Before, it just wasn’t fair to assess the former U.S. international in his first professional managerial assignment. Now he’s got more proper fitting pieces. If he can’t get it right by mid-season, is it so hard to envision a change?

In Seattle, Schmid still has the most important pieces that made Seattle an MLS Cup favorite last year. Plus, he’s got Jordan Morris. Surely you’ve heard about the country’s next great soccer star, right? (Sigh, we just don’t learn about the dangers of over-hyping young, mostly untested talent, do we?).

Two years ago the club nearly turned the page with Schmid; ownership acknowledged a close call in keeping Schmid around after 2013. Since then he has more or less held serve, but not much more. A fourth-place finish and second round playoff elimination last year were enough to carry the league’s all-time winningest coach into 2016.

But there are branches aplenty to be ducked for Schmid. First, Jason Kreis is the dark shadow lurking behind so many MLS managers, and nobody can dismiss his close ties with Sounders general manager Garth Lagerwey, not after what the pair built so smartly, previously, at Real Salt Lake. Kreis will be back in MLS sooner or later; book it.

There is Schmid’s health to be considered, too. Clearly, that trumps everything. And there is also this “end of era” feeling around teeming CenturyLink. Obafemi Martins, Clint Dempsey, Nelson Valdez, Chad Marshall, Brad Evans and Osvaldo Alonso are all north of 30 now. The stress of “now or never” will only grow with the first big injury to one of these backbone figures – and it is surely out there.

Cassar at Real Salt Lake and Mastroeni at Colorado are probably in most imminent danger. Neither made the playoffs last year, and it’s hard to say which failure hit hardest in the Rockies. RSL missed the post-season for the first time since 2007, a worthy streak for the small market operation. That won’t sit well with fans and team officials accustomed to better.

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Expectations don’t generally run as high in Commerce City outside of Denver, where Mastroeni has won just 17 of his first 68 matches as a pro coach (a 17-33-18 record in two seasons). Surely, the leash is chokingly short there, but then again who knows? So little seems to make sense when it comes to happenings around DSG Park, where the apparent lack of comprehensive plan remains perplexing.

(Oh, stop wondering if Kreis will “go home” to RSL. He won’t. Things have been different at Rio Tinto Stadium since owner Dell Loy Hansen took over, and the opinion that a real estate mogul who has no experience in sports management is “tearing his franchise to shreds” is increasingly popular. Kreis is too smart to jump back into that frying pan, especially as he is sure to have better options.)

Along the Eastern seaboard, three managers need to show their worth in 2016, although all three stressful situations have different frameworks.

Olsen is probably safe, but only because the cash-strapped operation cannot afford to replace him. Still, United has just one playoff series win since 2012. Olsen always sounds and looks like a guy who is feeling the pressure, so we’ll take his word for it.

Up the road in Philly, new whiz-kid technical director Earnie Stewart is in charge of personnel for the Union. Keeping Jim Curtin in place is the right thing to do; things around PPL Park have long been a complete mess, frankly, and that wasn’t Curtin’s fault. So for stability’s sake, having Curtin retain the coaching whistle makes sense. That said, a guy who went 10-17-7 last year and finished an unhappy ninth out of 10 teams won’t get much benefit of the doubt. He probably needs to produce in 2016. If things get off to a bad start, well, we mentioned Kreis being available, right? Stewart surely has already punched Kreis’ number into his smart phone.

Vieira has a pressure all his own, too. Kreis was saddled with a ridiculous distribution of midfield inertia (Frank Lampard and Andrea Pirlo) and that bandbox of a pitch at Yankee Stadium (bad for passing, but open season for goals off throw-ins!) and he still exceeded the number of wins for most expansion teams. Never mind that; NYCFC fired him.

Vieira is “next up,” and he totes the added burden of proving himself as a first-time pro manager.

South of there, Orlando City’s Heath did well in managing injuries and the usual mud puddle of a roster that expansion teams deal with. They very nearly made the playoffs. On the other hand, the franchise has high ambition, and a certain amount of front office instability and ongoing “new direction-itis” has to be unsettling for Heath.

Coyle gets a mulligan for his first season in MLS. The former Bolton manager didn’t make the playoffs with Houston in his initial American go-round – and don’t forget, it remains mathematically easier to make than to miss, as 12 of 20 teams slip past the post-season velvet ropes in MLS.

But he deserves a season with “his” players. Through December and January, Coyle had the chance to create the roster he deems best for Major League Soccer’s unique peculiarities. His changes included the bold move of parting ways with club favorite and do-all Brad Davis. So, add more heat to the heat and humidity around the club’s very orange downtown ground.