Ah, spring! What could go wrong?

Dustin Heddy with United Van Lines packs up gear in the St. Louis Cardinals clubhouse to be sent to the baseball team's spring training facility Thursday, Feb. 11, 2016, in St. Louis. Cardinals pitchers and catchers are scheduled to report to camp on Feb. 17, 2016, in Jupiter, Fla. (AP Photo/Jeff Roberson)

Credit: Jeff Roberson

Credit: Jeff Roberson

Dustin Heddy with United Van Lines packs up gear in the St. Louis Cardinals clubhouse to be sent to the baseball team's spring training facility Thursday, Feb. 11, 2016, in St. Louis. Cardinals pitchers and catchers are scheduled to report to camp on Feb. 17, 2016, in Jupiter, Fla. (AP Photo/Jeff Roberson)

The best part of spring training, which opens for most teams by the end of this week, is the optimism. Every team’s best-case scenario is still in play. Whatever jersey a player wears, he can slip it on with pride and channel his inner Lloyd Christmas, the naive dreamer from “Dumb and Dumber.”

A million-to-one shot? So you’re telling me there’s a chance!

Get ready for seven weeks of rosy forecasts around the major leagues. Every injury is healing well. Every prospect is the Next Big Thing. Every fading hitter has solved that pesky flaw in his swing. Maybe it will happen. Even if a front office has not designed a team to win, the players can always hope.

But remember this: For all that changes behind the scenes, every game still has a loser. It remains impossible for 30 teams to win at least 85 games and contend for a wild-card spot. Math is such a killjoy.

So as pitchers and catchers report to Florida and Arizona, here is the column nobody wants to read: a doomsday scenario, just below the cheery surface, that could thwart each team’s high hopes.

— Arizona Diamondbacks: Yet again, a team follows a winter of sizzle with a summer of fizzle. Zack Greinke’s record $34.4 million annual salary proves to be a drastic overpay as he begins to decline at age 32. Attendance continues to stagnate as the prospects traded for Shelby Miller and Jean Segura thrive elsewhere.

— Atlanta Braves: The veteran placeholders throughout the roster fail to hold up, and the Braves force-feed their prized young prospects into the majors before they are ready. The 20th and final season at Turner Field evokes the bleak days of old Fulton County Stadium in the late 1980s, with Freddie Freeman playing the role of Dale Murphy.

— Baltimore Orioles: The strategy of spending $207.8 million to keep Chris Davis, Darren O’Day and Matt Wieters — but of letting go of starter Wei-Yin Chen — proves to be disastrous. A rotation with a 4.53 ERA last season only gets worse, sentencing Baltimore to its first losing season since 2011.

— Boston Red Sox: Hanley Ramirez makes a disastrous transition to first base, leaving the Red Sox with nowhere to put him, while Rusney Castillo fails to seize the left-field job and center fielder Jackie Bradley Jr. loses the pop in his bat that he showed down the stretch last season. David Price helps the pitching staff, but a mediocre rotation behind him gives few leads for Craig Kimbrel, the new closer, to protect.

— Chicago Cubs: Last year’s workload catches up to Jake Arrieta; Kyle Schwarber can’t play defense; an aging Jon Lester and John Lackey rapidly decline; the patchwork bullpen frays; the left side of the infield collapses under the weight of strikeouts; Jason Heyward can’t handle center field; Joe Maddon switches to contact lenses and bans zoo animals from the clubhouse. Nah, who are we kidding? These are the Cubs. A championship is inevitable.

— Chicago White Sox: Todd Frazier, Brett Lawrie and Alex Avila are not enough to fix the lowest-scoring offense in the American League and the worst defensive team in the majors, and the White Sox spend another South Side summer in the shadow of the ascending Cubs.

— Cincinnati Reds: A proud franchise breaks its single-season record for losses (101) as a raw pitching staff is battered repeatedly at cozy Great American Ball Park. The lure of taking selfies with Brandon Phillips is not enough to draw fans, who sense no urgency to watch the famous plate discipline of Joey Votto, who is under contract through 2023.

— Cleveland Indians: In three years under manager Terry Francona, Cleveland has gone 29-44 before May 1 before rallying to finish with a winning record. A slow start bites the Indians again as their best hitter, Michael Brantley, recovers slowly from shoulder surgery and a hard-throwing rotation again fails to win consistently.

— Colorado Rockies: A collection of dynamic offensive players cannot counter the effects of Colorado’s annual seasonlong tryout camp on the mound. Nolan Arenado continues to dazzle at third base, at least — even after Von Miller of the Denver Broncos stole his title of best defensive player in the city.

— Detroit Tigers: The Tigers benefit from adding under-30 stars Justin Upton and Jordan Zimmermann. But their heavy reliance on veterans with recent injury concerns — and a shaky back end to the rotation — leaves them struggling to catch up to the sprightly younger teams in the AL.

— Houston Astros: For two-thirds of last season, the Astros were basically a .500 club, going 55-57 after May 30. A rotation with a limited track record, and the team’s persistent problem of winning on the road, slows the pace of a fast-rising franchise.

— Kansas City Royals: Ben Zobrist felt so warmly about his brief Kansas City experience that he gave his daughter the middle name Royal when she was born just after the World Series. That was touching, but Zobrist’s signing with the Cubs leaves a hole for his old team at second base. The Royals miss Zobrist’s versatility and extra-base pop, and their average rotation hurts them in a challenging AL Central.

— Los Angeles Angels: Only five teams had a worse on-base percentage last year than the Angels’ .307 — which is still better than the career OBP of their big offseason addition, sparkling shortstop Andrelton Simmons. With more than $40 million committed to starters Jered Weaver and C.J. Wilson, the Angels again fail to capitalize on the spectacular early prime of Mike Trout.

— Los Angeles Dodgers: Offseason operations limit Justin Turner (knee) and Yasmani Grandal (shoulder), Joc Pederson and Yasiel Puig continue to regress, and the pitching staff is all too ordinary besides Clayton Kershaw and Kenley Jansen. A three-year streak of National League West titles, without a pennant to show for it, comes to an end.

— Miami Marlins: Giancarlo Stanton fails to total 125 games played for the fourth time in five years; the back of the rotation never comes together; the new manager, Don Mattingly, is fired by the impatient owner, Jeffrey Loria; and Barry Bonds quickly loses interest in his new job as hitting coach.

— Milwaukee Brewers: The overhaul by general manager David Stearns is even more painful than expected. Ryan Braun’s offseason back surgery is an ominous signal as Braun starts the five-year, $105 million contract extension he signed in 2011, and the team searches in vain to find fair value in a deal for catcher Jonathan Lucroy.

— Minnesota Twins: After the Twins posted a winning record in 2015 despite a negative run differential (minus-4), their lack of power pitching and plate discipline causes them to stumble as they wait for pitcher Jose Berrios and center fielder Byron Buxton to join designated hitter Miguel Sano as the cornerstones of the franchise.

— New York Mets: The starters try hard to keep the ball out of play — to minimize the impact of the team’s shaky defense — but their 2015 workload wears them down. David Wright’s spinal stenosis limits him again, and while Yoenis Cespedes struggles in center field, he hits well enough to exercise his opt-out clause and repeat his protracted free-agent dance.

— New York Yankees: Having leaned on Carlos Beltran, Alex Rodriguez and Mark Teixeira for a combined 83 homers and 232 RBI last season, the Yankees see their aging sluggers crumble. The injury-prone starting rotation also falters, and all of those late-inning strikeouts from Dellin Betances, Andrew Miller and Aroldis Chapman cannot save the team from its first losing season since 1992.

— Oakland Athletics: For the second winter in a row, the A’s snagged a free agent fresh off a World Series appearance with the Royals. Billy Butler didn’t lift them last season, and now it’s Ryan Madson’s turn. The usual infusion of low-risk castoffs — Yonder Alonso, Henderson Alvarez, Rich Hill, Jed Lowrie — can’t keep up in a loaded AL West.

— Philadelphia Phillies: Like the giveaway of Hunter Pence in 2012, the Phillies’ recent trades of Cole Hamels and Ken Giles fail to land any impact stars. Comparisons to the dismal 76ers intensify, and even the Phanatic demands a trade.

— Pittsburgh Pirates: Three consecutive playoff trips in the 1990s ended short of the World Series. Three consecutive trips this decade have ended short of the NL Championship Series. The loss of three starters (A.J. Burnett, J.A. Happ and Charlie Morton) is too much to overcome for these Pirates, who endure another unfulfilling finish.

— St. Louis Cardinals: Two offseason thumb operations for the indispensable Yadier Molina highlight the age on a team stung by the departure of Jason Heyward, who cited the Cubs’ younger core as a reason for leaving. The steady influx of young talent slows in St. Louis as the Cubs build on their victory in the teams’ division series last fall.

— San Diego Padres: One year after a grand experiment gone awry, the Padres’ collection of middling, past-their-prime veterans and uninspiring young players leads to another dreary season. (This does not apply on home Fridays, when the long-awaited return of the brown jerseys — with brown-and-yellow caps — makes the Padres look like themselves at last.)

— San Francisco Giants: The Giants’ even-year magic runs out, as gambles on erratic starters Johnny Cueto and Jeff Samardzija backfire and hip surgery quickly ages speedy outfielder Denard Span, who starts a three-year contract at 32.

— Seattle Mariners: Jerry Dipoto’s flurry of complementary moves makes little impact, Robinson Cano cannot carry over his second-half momentum, and a leaky bullpen — with Steve Cishek and Joaquin Benoit now at the back end — helps Felix Hernandez remain the best active player to have never appeared in the postseason.

— Tampa Bay Rays: An average team (80-82 last season) struggles to do much better as it waits for a promising rotation to shake off injuries and come together behind Chris Archer. A resourceful mix-and-match offense can’t keep up with the thunder in the other AL East lineups.

— Texas Rangers: The pitching staff suffers more injury breakdowns, and Yu Darvish, with his surgically rebuilt elbow, does not return to ace status. The lineup cools off after a second-half surge last season, and the Rangers squander their final season with slugger Adrian Beltre under contract.

— Toronto Blue Jays: Losing David Price to the rival Red Sox shifts the balance of power in the AL East, and the rotation sags behind Marcus Stroman. Without the crafty Alex Anthopolous, who resigned as general manager, the Blue Jays fail to make the big move to take advantage of the last season of club control for Jose Bautista and Edwin Encarnacion.

— Washington Nationals: A familiar, discouraging Washington pattern extends to the ballpark and confounds the Nationals’ new manager, Dusty Baker, whose inspiring rhetoric cannot shake the infighting that preceded him into office, holding back the group from its grand potential.