WASHINGTON -- The Padres enter the second half of the season with sky-high aspirations, tempered by a few significant question marks. The most pressing of those questions marks: the starting rotation.

On paper, the Padres built perhaps the best rotation in baseball this season. It was OK during the first half, posting a 3.92 ERA, 11th best in the Majors. But lately, the rotation has begun to show cracks -- the types of issues that might necessitate an external fix.

• Padres Injuries and Roster Moves

Here's a look at where things stand in the Padres’ rotation entering the second half:

What's the status of the injured starters?
So this isn't great: The Padres open the second half of their season with four starting pitchers on the injured list for various reasons. That includes Ryan Weathers, who landed on the IL on Friday with a right heel bruise.

It's also not as bad as it sounds. Blake Snell's trip to the IL was the result of an illness. He’s expected back Saturday. Yu Darvish's hip ailment was similarly precautionary. The Padres remain optimistic that he will start Monday in Atlanta. He leads the team in innings by a sizeable margin, and pushing him back in the rotation following the All-Star break was partially designed to ease that burden.

The questions are greater with Weathers and Dinelson Lamet. The team is optimistic Weathers could return next weekend in Miami, but it’s too early to tell. Lamet, meanwhile, is working his way back from forearm inflammation. It has been a grind for him all season, with a slow buildup and three trips to the IL along the way. The Padres would love to have a healthy and thriving Lamet for the stretch run. They shouldn’t count on it.

What happens next?
Well, the Padres could cross their fingers and hope for quick recoveries from Weathers and Lamet. Or they could look to the trade market for reinforcements. Given the freewheeling nature of their general manager, expect the latter.

The Padres dealt for an ace last year, landing Mike Clevinger just before the Trade Deadline. Then they traded for Darvish, Snell and Joe Musgrove in the offseason. Don't ever rule out A.J. Preller from acquiring a frontline starter.

But the Padres' resources aren't as unlimited as they seemed last summer, and they're also on the lookout for a bat and some bullpen help.

With a handful of frontline starters already on board, it might be more likely they deal for a middle-of-the-rotation innings-eater, someone to take the burden off Weathers, Lamet and a struggling Chris Paddack.

What should we expect in the second half?
Ideally, the next few months won't see quite so much attrition. The Padres' 93 games in the first half were the most in the Majors, which conversely means they'll have more off-days than any other team in the second half.

“We’ve gone through what we consider the roughest part of the gauntlet in the schedule,” manager Jayce Tingler said. “I’m not saying the teams we play in the second half get any easier. But we do have some built-in off-days.”

The Padres employed a six-man rotation for stretches, but that seems unlikely moving forward. Still, with innings piling up -- well beyond their 2020 totals -- the Padres might devise a few tactics to extract quality over quantity.

In any case, the Padres need Musgrove and Darvish to rebound. They were excellent for most of the first three months, then tailed off at the end of the first half.

Is Gore a factor?
If everything goes smoothly at the big league level, then probably not. If Weathers and Lamet are healthy, if Paddack and Snell turn their struggles around, if the Padres trade for one more rotation arm, then there's no room for MacKenzie Gore.

But pitching plans never unfold so smoothly. It’s up to Gore to put himself in place for a callup. The Padres don't have much in the way of MLB-ready starting pitching depth at Triple-A. So why hasn't Gore earned it yet? Well, he hasn't earned it.

Gore, ranked by MLB Pipeline as the No. 6 overall prospect in baseball, is at the team's Spring Training complex in Arizona, working his way through mechanical troubles. He was initially sent there to allow time for his blister issues to be resolved, but that's already happened. Now, it's a matter of turning things back around after a poor start to the season -- a 5.85 ERA in six starts with El Paso.

"Is he the next man up? With Mack, we've got to feel like he's in a really good spot,” said Preller. “It's not about just coming up and holding your own. It's about him being the best version of himself. ... He's still working every single day, and we're hoping he's an option here at some point in the second half of the season."

Also worth noting: It’s unlikely Gore would be used as a trade chip. The Padres envision Gore ironing out his mechanical flaws and regaining his status as one of the game's elite prospects. They certainly don't want to sell low on a player with his upside.

What does the postseason rotation look like?
Don't ask the Padres; their focus is on getting there. Still, with San Diego's playoff odds sitting at 91%, according to FanGraphs, it would be foolish of the front office not to begin assessing its October rotation plans.

Currently, the Padres trail the Dodgers and Giants, and an appearance in the winner-take-all Wild Card Game seems likely. Darvish would be the go-to guy for a start like that one.

Behind Darvish, Musgrove sits in the No. 2 spot. But it's hard to guarantee a postseason start for anyone else. Snell probably warrants one, but he'll need to be a lot better than he was in the first half. There are also numerous question marks around Paddack, Weathers and Lamet.

The Trade Deadline is two weeks away. For Preller, the rotation -- specifically the playoff rotation -- should be at the forefront of his mind.