At least 25 of 30 Major League teams will see a reasonable path to the postseason by the time Opening Day rolls around. So offseason optimism isn't just for the Astros and Yankees.This is the best example of baseball's new landscape, one in which 21 of 30 teams have played

At least 25 of 30 Major League teams will see a reasonable path to the postseason by the time Opening Day rolls around. So offseason optimism isn't just for the Astros and Yankees.

This is the best example of baseball's new landscape, one in which 21 of 30 teams have played at least one postseason series the past five seasons and only five clubs made the playoffs in both 2016 and '17.

What's intriguing about 2018 is the large number of teams that have re-tooled their rosters around young players. Young players do not come with timetables (or guarantees), so these clubs can improve rapidly.

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We saw that in a dramatic way in 2017 as the Twins improved by 26 games, the D-backs by 24 and the Rockies by 12 on their big jumps back into the postseason.

Figuring out who the surprise teams of 2018 will be is the difficult part. But there are plenty of serious candidates.

Here's a look at five who appear to have a legitimate chance to jump into contention. To be helpful -- because what are we at MLB.com if not helpful -- I'm including a modest proposal for an additional upgrade. In addition to having a promising core of young talent, none of these clubs currently have any onerous long-term salary commitments, which could allow them to make some sneaky upgrades in this slow-moving free-agent market.

Braves

72-90 in 2017

There's so much talent on the Major League roster and in the Minor League pipeline that a huge turnaround is inevitable. Whether that happens in 2018 or '19 is the question. Progress this season could depend on three factors: the timetable for 20-year-old outfielder Ronald Acuna, a franchise-changing player; the development of infielders Dansby Swanson and Ozzie Albies ; and the emergence of all that young pitching in the Minors. Hiring Alex Anthopoulos to run baseball operations was a brilliant move. In short, this is a great time to be a Braves fan.

Modest proposal: Sign free-agent third baseman Todd Frazier . He would bring production at the position and he would also provide a role model for the young guys as they try to figure things out. And if they want to make a bit more of a splash, Mike Moustakas is still out there to fill their void at third.

Phillies

66-96 in 2017

There could still be growing pains, but the pieces are in place: Not just Odubel Herrera in center and newly signed Carlos Santana at first, but also Rhys Hoskins in left, Nick Williams in right, Jorge Alfaro behind the plate and J.P. Crawford and Cesar Hernandez in the middle infield. Also intriguing is a rotation in which eight young arms -- six of them 25 or under -- will compete for five spots.

Modest proposal: The Santana deal showed that this team could be players in free agency both this offseason and beyond, as Santana and Herrera are the only two players signed to long-term deals. With that in mind, this team should go sign a veteran starter. If Yu Darvish , Alex Cobb, Jacob Arrieta and Lance Lynn aren't in their price range, there are still options out there. For instance, Chris Tillman almost surely would take a one-year deal for a chance to reprove himself.

Athletics

75-87 in 2017

Now it's about starting pitching and how quickly prospects like lefty A.J. Puk get to the Majors, and if lefty Sean Manaea and righty Kendall Graveman take the next step forward. Offensively, once third baseman Matt Chapman and first baseman Matt Olson joined Khris Davis in the lineup, the A's took off, tying for the Major League lead in home runs (109) after the All-Star break. Stephen Piscotty -- the only player on this roster locked up beyond 2020 -- will start in right field with a chance to jump-start his career.

Modest proposal: Potentially affordable options to upgrade the rotation are still available, including Andrew Cashner , Tillman, Jason Vargas and Jaime Garcia . Any of them -- or some combination -- would provide some rotation certainty.

White Sox

67-95 in 2017

No team is more interesting than this one thanks to GM Rick Hahn's organizational rebuild around kids. With kids come uncertainty. But kids also bring hope. The White Sox could have two 24-year-olds ( Carson Fulmer and Reynaldo Lopez ) and a 23-year-old ( Lucas Giolito ) in their rotation, with flamethrower Michael Kopech -- the third-ranked right-handed pitching prospect in baseball, per MLB Pipeline, waiting in the wings. And then there is Yoan Moncada at second (age 22), Tim Anderson at short (age 24), and prospects like Eloy Jimenez on the verge. The young guys got valuable experience last season, and that learning process will continue in 2018. How quickly they settle in and show off their talent is the unknown. But it'll happen at some point.

Modest proposal: Welington Castillo is the only player with a guaranteed deal beyond this year, so this is a club that could dip into the free-agent pool at any time. For now, they could sign lefty reliever Tony Watson to improve the bullpen and give manager Rick Renteria a quality option late in games.

Padres

71-91 in 2017

This is the summer the young players who were thrown into the mix could take a nice step forward. That list includes center field Manuel Margot (age 23), catcher Austin Hedges (age 25), right fielder Hunter Renfroe (age 26) and righties Dinelson Lamet (age 25) and Luis Perdomo (age 24). GM A.J. Preller has added veteran arms Christopher Young and Tyson Ross to compete for jobs in the rotation. Some of the talented starters at Double-A should push for jobs by midseason, and at that point, improvement could come quickly.

Modest proposal: They have been linked to Eric Hosmer all offseason, but there are plenty of other smaller moves they could make to upgrade this roster. For example, they can go for another veteran starting pitcher hoping for a bounce-back type of season. Tillman, Francisco Liriano and Trevor Cahill would all make sense.