SAN DIEGO -- The Padres expect a significant amount of roster turnover this winter after a disheartening last-place finish in 2019.

Given the aggressive nature of general manager A.J. Preller and the organization's desire to open its contention window in 2020, there's zero chance that the current roster construction resembles the Opening Day squad.

Here's an early look at those Opening Day projections, based on the current group of players under contract. As a reminder, rosters expand to include 26 players next season.

Catcher

Locks: Francisco Mejía, Austin Hedges

Possibilities: Austin Allen, Luis Torrens, free agent/trade

No position features a more uncertain offseason outlook than catcher. It's possible the Padres look for a major shakeup and bring in an experienced backstop. It's possible they tinker -- perhaps dealing Hedges and giving opportunity to Torrens and Allen behind Mejía. And it's also possible they stand pat, trusting Mejía to take a step forward after an up-and-down rookie season, while Hedges serves as a defense-first backup. Time will tell.

First base

Locks: Eric Hosmer

Possibilities: Ty France

Despite consecutive subpar seasons from Hosmer, the Padres remain committed to him as their long-term first baseman. But the extent of that commitment might be tested if Hosmer continues to struggle against left-handed pitching. The veteran first baseman has been productive against righties. But his poor numbers against lefties have left open the possibility for a platoon. That remains unlikely at the start of the 2020 season, but it's a storyline worth watching.

Second base

Locks: None

Possibilities: Luis Urías, Greg Garcia, Ian Kinsler, France, trade/free agent

Urías has long been considered the Padres' second baseman of the future. That remains the case -- for now. But after a slow start to his big league career, it's possible the Padres explore other options this winter. They might look to bring in some competition. They also might use Urías in a package for, say, a front-line starting pitcher. But despite Urías' early struggles, there are reasons for optimism. He's only 22, and he batted .300/.371/.425 in September after he'd been given regular playing time.

Shortstop

Locks: Fernando Tatis Jr.

Possibilities: Urías

For years, the Padres were left looking for answers at shortstop nearly every offseason. Not anymore. Tatis burst onto the scene with a .317/.379/.590 slash line during his rookie season, and he added solid defense and elite baserunning. He'll need to move past a lower-back ailment that shortened his 2019 season. But Tatis has all the makings of a superstar.

Third base

Locks: Manny Machado

Possibilities: France

For all the question marks on the Padres' roster, they're in good hands for a long time on the left side of the infield with Tatis and Machado.

Outfield

Locks: Hunter Renfroe, Wil Myers

Possibilities: Manuel Margot, Josh Naylor, Franchy Cordero, Nick Martini, free agents/trades

Renfroe and Myers are locks only in the sense that if they aren't traded, they'll be on the Opening Day roster. But there's not a single outfielder on the Padres' 40-man who is guaranteed to be back next season. Renfroe is the likeliest to return, but there's an outside chance he's dealt. Myers, meanwhile, is still owed $68.5 million and is an obvious trade candidate. From the left side, the Padres have four options in Naylor, Cordero and Martini, but none have asserted themselves as a big league regular. San Diego outfielders were much, much better against lefties than righties last season, and one of Preller's primary objectives this winter is balancing that gap. Chances are, he looks externally for a left-handed bat via trade or free agency.

Starting pitchers

Locks: Chris Paddack, Garrett Richards

Possibilities: Dinelson Lamet, Joey Lucchesi, Eric Lauer, Cal Quantrill, Ronald Bolaños, MacKenzie Gore, Luis Patiño, Matt Strahm, Nick Margevicius, free agents/trades

Internally, the Padres are probably higher on their current rotation options than the rest of the baseball world is. Richards and Lamet are back from Tommy John surgery, Paddack could take another step toward acedom, and top prospects Gore and Patiño should arrive next summer as well. That said, Preller is going to be active on the starting pitching market this winter. The Padres need a front-line starter -- though it's unclear whether they'll look to free agency or trade acquire one. (They certainly have enough prospect capital for the latter option.) They could also use some depth, given how thin they were in the second half last season. Expect Preller to add (at least) two starters this winter.

Relief pitchers

Locks: Kirby Yates, Andres Muñoz, Strahm, José Castillo

Possibilities: Michel Baez, Luis Perdomo, David Bednar, Adrian Morejon, Miguel Diaz, Javy Guerra, Eric Yardley, Gerardo Reyes, Trey Wingenter, free agents/trades

In the bullpen, Preller's first order of business this winter will be locking up his closer. Yates was arguably the best reliever in baseball last season, and he's set to become a free agent after 2020. Both sides are open to an extension, and there's a decent chance it gets done this winter. Beyond Yates and flame-throwing righty Muñoz, the bullpen is full of question marks. Veteran Craig Stammen hits free agency, leaving a void in the middle innings. If Castillo is back to full health, that would go a long way toward filling it. The Padres also have a number of young arms with big-time potential who will compete for the back of the bullpen. But it's reasonable to expect a free-agent addition or two.