It's Memorial Day weekend, the unofficial start of trade season in baseball, and the Padres seem destined to be one of the sport's most active teams on the trade market again.

No, they don't have quite the same prospect capital as they did last summer. (That's the result of trades for Yu Darvish, Blake Snell, Joe Musgrove, Mike Clevinger and Austin Nola, among others.)

But general manager A.J. Preller still has a relatively deep system to work with -- and plenty of incentive to improve his roster, with the margins in the National League West razor thin.

Here's what Preller and the Padres will be looking for:

An outfield bat

The Padres were never going to push the panic button in April, when Jurickson Profar and Tommy Pham were both struggling. They knew both players had extensive track records, and the sample sizes were small.

Sure enough, Pham owns a .771 May OPS after an ugly.503 mark in April. Profar has shown some positive signs lately, too. (Now it's Wil Myers who’s mired in a slump in right field.)

In any case, the Padres feel they already have enough to cover those two corner-outfield spots. But Preller isn't one to leave any stone unturned. And while there's been some clamor for a big-time outfield bat, it's possible Preller simply looks to augment his depth a bit.

There is, however, a noteworthy flaw in that plan. If the Padres were to trade for an outfield bench bat, where's the roster space? Jorge Mateo is out of options, and the Padres view Mateo very favorably, specifically considering the impact he can make on the basepaths come October. If, indeed, the Padres make a trade to boost their outfield depth, it might only be in response to an injury.

A depth starting pitcher

The Padres already have a six-man rotation, and top prospect MacKenzie Gore waiting in Triple-A. But the reality is: Two of those starters have their workloads strictly monitored, and Gore simply hasn't proven himself ready for the bigs yet.

Right now, it's putting an undue tax on the Padres' bullpen (which, it should be noted, has risen to the challenge). Still, Ryan Weathers is a 21-year-old rookie who has never pitched more than 100 innings in a season. Dinelson Lamet is building up slowly from a UCL strain last September, and hasn't thrown more than three innings in any of his outings.

So, yeah, the Padres could probably use a rotation boost. Don't expect Preller to add another ace. (Though those exact words were probably uttered last January after Darvish and Snell arrived, yet Preller still managed to land Musgrove.) But a move for an innings-eating depth starter -- even if he's unlikely to crack the postseason roster -- might be prudent.

A reliever, preferably left-handed

Depending on the extent of Drew Pomeranz's injury, this might suddenly be the Padres' most pressing need. Consider what has happened to their left-handed relief options this season:

Pomeranz is on the IL with a shoulder impingement and recently had a setback. José Castillo and Adrian Morejon are out for the year due to Tommy John surgery. Matt Strahm hasn't pitched yet after offseason knee surgery. And Weathers has been moved to the rotation.

Tim Hill has done an incredible job shouldering that burden, with a 2.21 ERA across 23 outings. But Hill could use some help. If the Padres really wanted to go big, they could make the Josh Hader splash that has been bandied about for over a year. But Hader won't come cheap. (Plus, as the Padres can attest after seven tightly contested games already this season, the Brewers are legitimate playoff contenders, and Hader is a big reason why.)

The likelier option is a Hill-esque lefty for the middle innings. That's well within the budget. (Last year, the Padres landed Hill for Franchy Cordero and Ronald Bolaños in one of Preller's most underrated moves as GM.)

A depth catcher

The Padres constructed a deep roster without many flaws, but one area in which they've been exposed is organizational catching depth. Since last year's Trade Deadline, they've sent Francisco Mejía, Austin Hedges, Luis Torrens and Blake Hunt elsewhere.

That wouldn't have been an issue had Nola been healthy. He and Caratini are a huge upgrade on the previous catching situation. But Nola just landed on the IL for the second time this season -- this time with a left-knee sprain.

The Padres are optimistic Nola will return soon. But there's room for a third catcher -- one who has options and can be moved freely between Triple-A and the Majors -- on this roster. Perhaps the Padres envisioned that being No. 3 prospect Luis Campusano, but his first two months haven't gone as planned. They promoted Webster Rivas on Friday, but the 11-year journeyman might only be a stopgap.

There are fringe big league catchers available for an affordable price. It almost certainly won't be the most exciting trade the Padres make this summer. But don't be surprised if it's the first one.